CVE-2022-35961: ECDSA signature malleability in OpenZeppelin Contracts

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-08-15 · updated 2026-06-17
Weakness: CWE-354

Description

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.

Affected products

openzeppelin-contracts: from 4.1.0 before 4.7.3 — fixed in 4.7.3
OpenZeppelin Contracts Upgradeable: from 4.1.0 before 4.7.3 — fixed in 4.7.3

How to fix

Upgrade to a fixed version: openzeppelin-contracts 4.7.3; OpenZeppelin Contracts Upgradeable 4.7.3. Check the vendor advisory for mitigations.

References

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