Ensure Slippage and Deadline Checks in UniswapV3 Swap

[c4-bot-4]

Lines of code

https://github.com/code-423n4/2024-01-decent/blob/main/src/swappers/UniSwapper.sol#L130
https://github.com/code-423n4/2024-01-decent/blob/main/src/swappers/UniSwapper.sol#L150
https://github.com/Uniswap/v3-periphery/blob/697c2474757ea89fec12a4e6db16a574fe259610/contracts/base/PeripheryValidation.sol#L8

Vulnerability details

Impact

missing zero check:

The amountOutMinimum is intended to be set to swapParams.amountOut, but it is crucial to verify that it is not checked with a zero value. Allowing amountOutMinimum = 0 informs the swap that the caller is willing to accept a minimum amount of 0 output tokens, exposing the user to a potential catastrophic loss of funds through MEV bot sandwich attacks.

missing deadline:

The deadline parameter allows the caller to specify a time limit by which the transaction must be executed. Without a deadline parameter, the transaction may linger in the mempool and be executed at a later time, potentially resulting in a worse price for the user.

uniswap deadline checks

It is also important to include an expiration deadline to prevent slippage attacks. If the deadline parameter is commented out, it can lead to a zero start for the deadline parameter, preventing any transaction from occurring. This is because SwapRouter.sol in UniswapV3 has a checkDeadline modifier that verifies if block.timestamp >= deadline; otherwise, it reverts.

Proof of Concept

The missing zero check and the absence of a set deadline can be identified in the following:

https://github.com/code-423n4/2024-01-decent/blob/main/src/swappers/UniSwapper.sol#L130

https://github.com/code-423n4/2024-01-decent/blob/main/src/swappers/UniSwapper.sol#L150

https://github.com/Uniswap/v3-periphery/blob/697c2474757ea89fec12a4e6db16a574fe259610/contracts/base/PeripheryValidation.sol#L8

Tools Used

Manual

Recommended Mitigation Steps

Check whether swapParams.amountOut is zero or not, and set the correct deadline.

Assessed type

Uniswap

[c4-pre-sort]

raymondfam marked the issue as insufficient quality report

[c4-pre-sort]

raymondfam marked the issue as duplicate of #24

[raymondfam]

Slippage is already in place as commented in SwapParams.

[c4-judge]

alex-ppg marked the issue as unsatisfactory:
Invalid