The Standard

Summary

Return values of approve() not checked

Vulnerability Details

Not all IERC20 implementations revert() when there's a failure in approve(). The function signature has a boolean return value and they indicate errors that way instead. By not checking the return value, operations that should have marked as failed, may potentially go through without actually approving anything

Impact

It may cause a situation where the approve is not successful and the protocol continues without considering it.

Tools Used

Manual Review

Recommendations

Consider using SafeERC20.