Alchemix Transmuter

Code Snippets

https://github.com/Cyfrin/2024-12-alchemix/blob/82798f4891e41959eef866bd1d4cb44fc1e26439/src/StrategyOp.sol#L79-L89

Summary

The claimAndSwap function's deadline protection is inadequate, making it susceptible to exploitation by front-runners or any parties capable of manipulating transaction sequencing to gain an unfair advantage over legitimate keepers.

Vulnerability Details

claimAndSwap function uses _swapUnderlyingToAsset function to swap underlying asset. Accordingly, _swapUnderlyingToAsset function interacts with router using swapExactTokensForTokens function:

block.timestamp is utilized in purpose of slippage control.

By depending on the current timestamp to enforce deadlines, the system inadvertently weakens the intended purpose of establishing a strict time limit, as this timestamp can be delayed or manipulated at will.

In the absence of a clearly defined and immutable deadline determined by the keeper, this mechanism unintentionally creates opportunities for malicious actors, such as front-runners and MEV bots, to exploit the system. These entities can manipulate transaction timing and sequence to act in their own interest, thereby compromising the fairness and efficiency intended for honest participants.

Impact

The reliance on block.timestamp for slippage control undermines the integrity of the system, enabling malicious actors like front-runners to manipulate transaction timing and sequencing, leading to unfair advantages, compromised security, and potential financial losses for honest participants.

Tools Used

Manual Review

Recommendations

Add a strict and user-chosen deadline parameter to the claimAndSwap() to ensure proper slippage control.