CVE-2021-3762 is a critical-severity (CVSS 9.8) Path Traversal vulnerability in github.com/quay/claircore. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2021-3762 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Path traversal in claircore
Real-World Exposure
github.com/quay/claircore🐹github.com/quay/claircore🐹github.com/quay/claircoreReal-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
A directory traversal vulnerability was found in the ClairCore engine of Clair. An attacker can exploit this by supplying a crafted container image which, when scanned by Clair, allows for arbitrary file write on the filesystem, potentially allowing for remote code execution.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/quay/claircore | all versions | 0.4.8 |
| 🐹Go | github.com/quay/claircore | ≥ 1.0.0&&< 1.1.0 | 1.1.0 |
| 🐹Go | github.com/quay/claircore | ≥ 0.5.0&&< 0.5.5 | 0.5.5 |
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/quay/claircore. 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/quay/claircore to 0.4.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3762 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-2021-3762 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-2021-3762. 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-2021-3762 in your dependencies?
O3 detects CVE-2021-3762 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.