MorpheusAI

Summary

The protocol is using block.timestamp as the deadline argument while interacting with the Uniswap NFT Position Manager and Swap Router, which completely defeats the purpose of using a deadline.

Vulnerability Details

Actions in the Uniswap NonfungiblePositionManager and SwapRouter contract are protected by a deadline parameter to limit the execution of pending transactions. Functions that modify the liquidity of the pool check this parameter against the current block timestamp in order to discard expired actions.

These interactions are presented in the L2TokenReceiver contract. The functions swap() and increaseLiquidityCurrentRange() call their corresponding functions in the Uniswap Position Manager and Swap Router, providing block.timestamp as the argument for the deadline parameter.

Impact

Using block.timestamp as the deadline is effectively a no-operation that has no effect nor protection. Since block.timestamp will take the timestamp value when the transaction gets mined, the check will end up comparing block.timestamp against the same value, i.e. block.timestamp <= block.timestamp (see https://github.com/Uniswap/v3-periphery/blob/697c2474757ea89fec12a4e6db16a574fe259610/contracts/base/PeripheryValidation.sol#L7).

Failure to provide a proper deadline value enables pending transactions to be maliciously executed at a later point. Transactions that provide an insufficient amount of gas such that they are not mined within a reasonable amount of time, can be picked by malicious actors or MEV bots and executed later in detriment of the submitter.

See this issue for an excellent reference on the topic (the author runs a MEV bot).

Tools Used

Manual Review

Recommendations

Allow the owner to manually specify the deadline parameter.