Description
OpenZeppelin Contracts is a library for secure smart contract development. Starting in version 4.0.0 and prior to version 4.9.3, contracts using `ERC2771Context` along with a custom trusted forwarder may see `_msgSender` return `address(0)` in calls that originate from the forwarder with calldata shorter than 20 bytes. This combination of circumstances does not appear to be common, in particular it is not the case for `MinimalForwarder` from OpenZeppelin Contracts, or any deployed forwarder the team is aware of, given that the signer address is appended to all calls that originate from these forwarders. The problem has been patched in v4.9.3.
Remediation
References
https://github.com/OpenZeppelin/openzeppelin-contracts/commit/9445f96223041abf2bf08daa56f8da50b674cbcd
https://github.com/OpenZeppelin/openzeppelin-contracts/pull/4484
https://github.com/OpenZeppelin/openzeppelin-contracts/releases/tag/v4.9.3
https://github.com/OpenZeppelin/openzeppelin-contracts/pull/4481
https://github.com/OpenZeppelin/openzeppelin-contracts/commit/e4435eed757d4309436b1e06608e97b6d6e2fdb5
https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-g4vp-m682-qqmp