Headline
CVE-2022-31170
OpenZeppelin Contracts is a library for smart contract development. Versions 4.0.0 until 4.7.1 are vulnerable to ERC165Checker reverting instead of returning false. ERC165Checker.supportsInterface is designed to always successfully return a boolean, and under no circumstance 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-165 as expected, specifically if it returns a value other than 0 or 1. The contracts that may be affected are those that use ERC165Checker to check for support for an interface and then handle the lack of support in a way other than reverting. The issue was patched in version 4.7.1.
Impact
ERC165Checker.supportsInterface is designed to always successfully return a boolean, and under no circumstance 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-165 as expected, specifically if it returns a value other than 0 or 1.
The contracts that may be affected are those that use ERC165Checker to check for support for an interface and then handle the lack of support in a way other than reverting.
Patches
The issue was patched in 4.7.1.
References
#3552
For more information
If you have any questions or comments about this advisory, or need assistance deploying the fix, email us at [email protected].
Related news
### Impact `ERC165Checker.supportsInterface` is designed to always successfully return a boolean, and under no circumstance 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-165 as expected, specifically if it returns a value other than 0 or 1. The contracts that may be affected are those that use `ERC165Checker` to check for support for an interface and then handle the lack of support in a way other than reverting. ### 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 [[email protected]](mailto:[email protected]).