RebateFi Hook
First Flight #53
Beginner FriendlyDeFi
100 EXP
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Submission Details
Impact: high
Likelihood: high
Invalid

Uncorrect permission on `getHookPermission()` function

zyrrow

Root + Impact

Function getHookPermission() doesn't make possible to enables dynamic fees making the RebateFiHook protocol useless.

Description

On Uniswap v4 , Hook are optional and customizable by developpers to fit their own goal. On this case the protocol's purpose is to encourage peoples to buy ReFi token by making fee = 0 and discourage peoples to sell to dumping and generate protocol revenue by adding fee.

On uniswap v4 each hook choose the function that they can access by using the getHookPermission() function. These function are stored in the 160 bit address of the contract. So if there are missing permission on critical function this can't be changed without redeploying another contract.

The problem with the function getHookPermission() is that the function beforeSwapReturnDelta and afterSwapReturnDelta are false , so that the hook can never call them , and these are the function (atleast one of t hem depend on design) that permit to applicate fee neither pricing or swap result :

function getHookPermissions() public pure override returns (Hooks.Permissions memory) {
return Hooks.Permissions({
beforeInitialize: true,
afterInitialize: true,
beforeAddLiquidity: false,
afterAddLiquidity: false,
beforeRemoveLiquidity: false,
afterRemoveLiquidity: false,
beforeSwap: true,
afterSwap: false,
beforeDonate: false,
afterDonate: false,
beforeSwapReturnDelta: false,@> FALSE HERE
afterSwapReturnDelta: false,@> FALSE HERE
afterAddLiquidityReturnDelta: false,
afterRemoveLiquidityReturnDelta: false
});
// Root cause in the codebase with @> marks to highlight the relevant section

Risk

Likelihood:

  • Without modification it would be always.

Impact:

  • The entire protocol is break.

Proof of Concept

- Admin try to applicate his logic fee
- He call function to modifiate fee
- Contract can't reach the function
- Protocol is break

Recommended Mitigation

Allow these fonction on getHookPermission then add your logic on the contract.

- remove this code
​
beforeSwapReturnDelta: false,
//or
afterSwapReturnDelta: false
+ add this code
beforeSwapReturnDelta: true,
//or
afterSwapReturnDelta: true,
Updates

Lead Judging Commences

chaossr Lead Judge 8 days ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement

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