GHSA-fr8m-434r-g3xp
MEDIUMgnark-crypto doesn't range check input values during ECDSA and EdDSA signature deserialization
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/consensys/gnark-cryptoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
During deserialization of ECDSA and EdDSA signatures gnark-crypto did not check that the values are in the range [1, n-1] with n being the corresponding modulus (either base field modulus in case of R in EdDSA, and scalar field modulus in case of s,r in ECDSA and s in EdDSA). As this also allowed zero inputs, then it was possible to craft a signature which lead to null pointer dereference, leading to denial-of-service of an application. This also enabled weak signature malleability when the users assumed uniqueness of the serialized signatures (but not the underlying modulo reduced values).
We are not aware of any users impacted by the bug. The implemented signature schemes in gnark-crypto complement the in-circuit versions in gnark, allowing to have end-to-end tests.
Patches
The issue was patched in PR #449. The fix returns an error during deserialization if the values do not belong to the ranges [1, n-1].
The fix is included in release v0.12.0 and upwards.
Workarounds
Users can manually validate the inputs to be in corresponding ranges when using serialized signatures (or digests of them) as unique keys.
To address the denial-of-service, the users can install hook to recover panics and recover
Resources
- Verichains advisory for signature malleability.
- Fix https://github.com/Consensys/gnark-crypto/pull/449
- Go blog post "Defer, Panic, and Recover"
- gnark v0.12.0
Acknowledgement
Lack of range checks leading to signature malleability was reported by Verichains.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/consensys/gnark-crypto | all versions | 0.12.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/consensys/gnark-crypto. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/consensys/gnark-crypto to 0.12.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fr8m-434r-g3xp is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-fr8m-434r-g3xp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-fr8m-434r-g3xp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-fr8m-434r-g3xp in your dependencies?
O3 detects GHSA-fr8m-434r-g3xp across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.