CVE-2024-21664 is a medium-severity (CVSS 4.3) NULL Pointer Dereference vulnerability in github.com/lestrrat-go/jwx. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2024-21664 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Parsing JSON serialized payload without protected field can lead to segfault
Real-World Exposure
github.com/lestrrat-go/jwx🐹github.com/lestrrat-go/jwx/v2Real-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
jwx is a Go module implementing various JWx (JWA/JWE/JWK/JWS/JWT, otherwise known as JOSE) technologies. Calling jws.Parse with a JSON serialized payload where the signature field is present while protected is absent can lead to a nil pointer dereference. The vulnerability can be used to crash/DOS a system doing JWS verification. This vulnerability has been patched in versions 2.0.19 and 1.2.28.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/lestrrat-go/jwx | ≥ 1.0.8&&< 1.2.28 | 1.2.28 |
| 🐹Go | github.com/lestrrat-go/jwx/v2 | all versions | 2.0.19 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/lestrrat-go/jwx. 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/lestrrat-go/jwx to 1.2.28 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-21664 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 CVE-2024-21664 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 CVE-2024-21664. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-21664 in your dependencies?
O3 detects CVE-2024-21664 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.