Era

Summary

The _approveFundsToAssetRouter from L1ERC20Bridge.sol function uses _token.approve and checks the success value. This approach will revert for tokens that do not return a boolean value on approval.

Vulnerability Details

Some ERC20 tokens do not return a boolean value on the approve function, such as USDT. The current implementation of L1ERC20Bridge assumes that the approve function will always return a boolean value, which can lead to unexpected reverts.

Impact

The function will revert for tokens that do not return a boolean value on the approve function, causing a denial of service in L1ERC20Bridge.deposit for those tokens.

Tools Used

Manual review.

Recommendations

Use SafeERC20.forceApprove from OpenZeppelin to correctly handle tokens that do not return boolean values on approve.