What the vulnerability does
01Description
OpenZeppelin Contracts is a library for secure smart contract development. The functions `ECDSA.recover` and `ECDSA.tryRecover` are vulnerable to a kind of signature malleability due to accepting EIP-2098 compact signatures in addition to the traditional 65 byte signature format. This is only an issue for the functions that take a single `bytes` argument, and not the functions that take `r, v, s` or `r, vs` as separate arguments. The potentially affected contracts are those that implement signature reuse or replay protection by marking the signature itself as used rather than the signed message or a nonce included in it. A user may take a signature that has already been submitted, submit it again in a different form, and bypass this protection. The issue has been patched in 4.7.3.
