Closed code423n4 closed 1 year ago
0xA5DF marked the issue as low quality report
Known issue, was reported in a previous audit and the project explains well why it's not an issue
0xA5DF marked the issue as primary issue
Known issue, was reported in a previous audit and the project explains well why it's not an issue
Exactly. This issue is out of scope for this audit.
hansfriese marked the issue as unsatisfactory: Out of scope
Lines of code
https://github.com/code-423n4/2023-04-frankencoin/blob/main/contracts/ERC20PermitLight.sol#L21
Vulnerability details
Impact
Ethereum contracts often assumes that the signature is unique, but signatures can be altered without the possession of the private key and still be valid. The EVM specification defines several so-called ‘precompiled’ contracts one of them being ecrecover which executes the elliptic curve public key recovery. A malicious user can slightly modify the three values v, r and s to create other valid signatures. A system that performs signature verification on contract level might be susceptible to attacks if the signature is part of the signed message hash. Valid signatures could be created by a malicious user to replay previously signed messages. Resource: https://swcregistry.io/docs/SWC-117
This can lead to user's loosing funds or any unexpected behaviour.
Proof of Concept
Tools Used
Mannual Review
Recommended Mitigation Steps
Use ECDSA contract from OpenZeppelin or add additional check for s: