Part 2

Summary

The UniswapV3Adapter and UniswapV2Adapter contracts inherit a global deadline from BaseAdapter instead of allowing transactions to specify their own deadline values. This exposes transactions to MEV attacks, price slippage, and potential failures if the deadline is too short, reducing flexibility and security for time-sensitive trades.

Vulnerability Details

The UniswapV3Adapter and UniswapV2Adapter contracts utilize a global deadline rather than allowing each transaction to specify its own deadline. In the executeSwapExactInputSingle and executeSwapExactInput functions, the deadline is taken from BaseAdapter contract instead of being explicitly provided in each trade. Uniswap’s native interface supports setting a per-transaction deadline, ensuring users can define a custom validity period for each trade.

src/utils/dex-adapters/BaseAdapter.sol:setDeadline#L153-L162

src/utils/dex-adapters/UniswapV2Adapter.sol:executeSwapExactInput#L131

src/utils/dex-adapters/UniswapV2Adapter.sol:executeSwapExactInputSingle#L101

src/utils/dex-adapters/UniswapV3Adapter.sol:executeSwapExactInput#L136

src/utils/dex-adapters/UniswapV3Adapter.sol:executeSwapExactInputSingle#L106

Impact

1. MEV Exploitation Risk: If the global deadline is too long, transactions may remain in the mempool for extended periods, making them susceptible to MEV attacks, such as front-running or sandwich attacks.

2. Price Slippage Risk: A long deadline increases the likelihood of significant price fluctuations before execution, potentially leading to worse trade execution than expected.

3. Reduced User Control: Users are unable to set specific deadlines for different transactions, reducing flexibility in executing time-sensitive trades.

4. Transaction Failures: If the global deadline is too short, valid trades may fail unnecessarily.

Tools Used

Manual Code Review

Recommendations

It is recommended to add a deadline parameter to SwapExactInputSinglePayload and and SwapExactInputPayload to use the transaction-specific deadline in uniswap calls. If a transaction-specific deadline is not provided, fallback to a reasonable default instead of a global value.