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. A fix is available for github.com/quay/claircore — see the affected versions and patch details below.
Path traversal in claircore
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-3762 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
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 | 0.4.8go get github.com/quay/claircore@v0.4.8 |
| 🐹Go | github.com/quay/claircore | ≥ 1.0.0&&< 1.1.0 | 1.1.0go get github.com/quay/claircore@v1.1.0 |
| 🐹Go | github.com/quay/claircore | ≥ 0.5.0&&< 0.5.5 | 0.5.5go get github.com/quay/claircore@v0.5.5 |
Affected Products
clairredhatquayredhatResearch 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Only a single version of Red Hat Quay, 3.5.6 is affected by this vulnerability. All previous released versions of Red Hat Quay are not affected by this vulnerability. The overall vulnerability is rated as Critical for the ClairCore engine, but only rated Important for the Red Hat Quay product. In Red Hat Quay, Clair…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2021-3762 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Quay 3 | quay/clair-rhel8:v3.5.7-8 | RHSA-2021:3665 |
Frequently Asked Questions
Is CVE-2021-3762 in your dependencies?
Find it across Go, including transitive dependencies.