Summary

Contracts use infinite approvals with no means to revoke

Vulnerability Details

Infinite approvals on external contracts can be dangerous if the target becomes compromised.

Impact

See here (https://revoke.cash/exploits) for a list of approval exploits. The following contracts are vulnerable to such attacks since they have no functionality to revoke the approval (call approve with amount 0)

Tools Used

Manual Review

Recommendations

Consider enabling the contract to revoke approval in emergency situations.