Advisory Weakness Curation

OpenZeppelin Contracts's SignatureChecker may revert on invalid EIP-1271 signers ### Impact `SignatureChecker.isValidSignatureNow` is not expected to revert. However, an incorrect assumption about Solidity 0.8's `abi.decode` allows some cases to revert, given a target contract that doesn't implement EIP-1271 as expected. The contracts that may be affected are those that use `SignatureChecker` to check the validity of a signature and handle invalid signatures in a way other than reverting. We believe this to be unlikely. ### Patches The issue was patched in 4.7.1. ### References https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3552 ### For more information If you have any questions or comments about this advisory, or need assistance deploying the fix, email us at [security@openzeppelin.com](mailto:security@openzeppelin.com).

Improper Input Validation OpenZeppelin Contracts is a library for smart contract development. Versions 4.1.0 until 4.7.1 is vulnerable to the SignatureChecker reverting. `SignatureChecker.isValidSignatureNow` is not expected to revert. However, an incorrect assumption about Solidity 0.8's `abi.decode` allows some cases to revert, given a target contract that does not implement EIP-1271 as expected. The contracts that may be affected are those that use `SignatureChecker` to check the validity of a signature and handle invalid signatures in a way other than reverting. The issue was patched in version 4.7.1.

Improper Input Validation OpenZeppelin Contracts is a library for smart contract development. Versions 4.1.0 until 4.7.1 is vulnerable to the SignatureChecker reverting. `SignatureChecker.isValidSignatureNow` is not expected to revert. However, an incorrect assumption about Solidity 0.8's `abi.decode` allows some cases to revert, given a target contract that does not implement EIP-1271 as expected. The contracts that may be affected are those that use `SignatureChecker` to check the validity of a signature and handle invalid signatures in a way other than reverting. The issue was patched in version 4.7.1.