Revert Lend - lightoasis's results

Lines of code

https://github.com/code-423n4/2024-03-revert-lend/blob/435b054f9ad2404173f36f0f74a5096c894b12b7/src/V3Vault.sol#L1066

Vulnerability details

Vulnerability

The vulnerability and impact is similar to Particle M-02 where block.timestamp was used as the deadline argument while interacting with the Uniswap NFT Position Manager. Using block.timestamp as a deadline completely defeats the purpose of using a deadline.

Impact

Actions in the Uniswap NonfungiblePositionManager 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 with the Uniswap position are present in the V3Vault contract. Specifically, _sendPositionValue() which is called during liquidate() calls onfungiblePositionManager.decreaseLiquidity() while providing block.timestamp as the argument for the deadline parameter: V3Vault.sol#L1066

if (liquidity > 0) {
            nonfungiblePositionManager.decreaseLiquidity(
                INonfungiblePositionManager.DecreaseLiquidityParams(tokenId, liquidity, 0, 0, block.timestamp)
            );
        }

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 here).

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 issues for an excellent reference on the topic (the author runs a MEV bot).

Recommendation

Add a deadline parameter for the INonfungiblePositionManager.DecreaseLiquidityParams() call

Assessed type

Uniswap