Vanguard
First Flight #56
Beginner FriendlyDeFiFoundry
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Submission Details
Impact: high
Likelihood: high

Deploy Script Uses Wrong Hook Flag (BEFORE_INITIALIZE Instead of AFTER_INITIALIZE)

Author Revealed upon completion

Description

  • Uniswap V4 hooks must have their address match specific bit flags indicating which hook callbacks they implement. The HookMiner is used to find a salt that produces an address with the correct flags.

  • The deploy script mines for an address with BEFORE_INITIALIZE_FLAG, but the contract actually implements afterInitialize (setting afterInitialize: true in permissions). This mismatch will cause deployment validation to fail.

// deployLaunchHook.s.sol - WRONG FLAG
uint160 flags = uint160(Hooks.BEFORE_SWAP_FLAG | Hooks.BEFORE_INITIALIZE_FLAG);
// @> Should be AFTER_INITIALIZE_FLAG
// TokenLaunchHook.sol - Actual permissions
function getHookPermissions() public pure override returns (Hooks.Permissions memory) {
return Hooks.Permissions({
beforeInitialize: false, // @> Not using beforeInitialize
afterInitialize: true, // @> Using afterInitialize
// ...
beforeSwap: true,
// ...
});
}

Risk

Likelihood:

  • This will occur on every deployment attempt using the provided script

  • The address mined will have incorrect flag bits

Impact:

  • Uniswap V4 PoolManager will reject the hook during pool initialization due to flag mismatch

  • Protocol cannot be deployed using the provided deployment script

  • Developers must manually fix the script before any deployment

Proof of Concept

Compare flag values - script uses BEFORE_INITIALIZE_FLAG, hook requires AFTER_INITIALIZE_FLAG.

function test_DeployScriptWrongFlag() public {
// The deploy script uses:
uint160 wrongFlags = uint160(Hooks.BEFORE_SWAP_FLAG | Hooks.BEFORE_INITIALIZE_FLAG);
// But the hook implements:
uint160 correctFlags = uint160(Hooks.BEFORE_SWAP_FLAG | Hooks.AFTER_INITIALIZE_FLAG);
// These will mine different addresses
assertNotEq(wrongFlags, correctFlags, "Flags should be different");
// Deployment with wrong flags will fail Uniswap's hook validation
}

Recommended Mitigation

Change flag from BEFORE_INITIALIZE_FLAG to AFTER_INITIALIZE_FLAG.

// script/deployLaunchHook.s.sol
​
function run() public {
// hook contracts must have specific flags encoded in the address
- uint160 flags = uint160(Hooks.BEFORE_SWAP_FLAG | Hooks.BEFORE_INITIALIZE_FLAG);
+ uint160 flags = uint160(Hooks.BEFORE_SWAP_FLAG | Hooks.AFTER_INITIALIZE_FLAG);
​
// Mine a salt that will produce a hook address with the correct flags
// ...
}

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