Signature Replay Attack Vulnerability in Airdrop Mechanism
Summary
The AirdropRecipient contract is vulnerable to signature replay attacks due to the lack of nonce management, timestamping, and contextual binding in the signature verification process. This vulnerability can lead to unauthorized claims and financial losses.
Vulnerability Detail
The contract AirdropRecipient uses SignatureCheckerLib.isValidSignatureNow for verifying signatures. However, this method does not inherently protect against replay attacks. Without a nonce, timestamp, or contextual data in the signed message, valid signatures can be reused, allowing unauthorized parties to claim airdrops multiple times in diffrent chains.
Impact
Unauthorized claims of airdrops through replayed valid signatures.
Potential financial losses and depletion of airdrop resources.
0xBhumii
Medium
Signature Replay Attack Vulnerability in
AirdropMechanismSummary
The
AirdropRecipientcontract is vulnerable to signature replay attacks due to the lack of nonce management, timestamping, and contextual binding in the signature verification process. This vulnerability can lead to unauthorized claims and financial losses.Vulnerability Detail
The contract
AirdropRecipientusesSignatureCheckerLib.isValidSignatureNowfor verifying signatures. However, this method does not inherently protect against replay attacks. Without a nonce, timestamp, or contextual data in the signed message, valid signatures can be reused, allowing unauthorized parties to claim airdrops multiple times in diffrent chains.Impact
Unauthorized claims of airdrops through replayed valid signatures. Potential financial losses and depletion of airdrop resources.
Code Snippet
https://github.com/sherlock-audit/2024-08-flayer/blob/main/flayer/src/contracts/utils/AirdropRecipient.sol#L58C1-L63C1
Tool used
Manual Review
Recommendation
Include Nonce,ChainId or Timestamp during the signature verifications.