CVE-2021-3602
MEDIUMCVE-2021-3602 is a medium-severity (CVSS 5.5) Information Exposure vulnerability in github.com/containers/buildah. O3 Security confirms whether CVE-2021-3602 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Buildah processes using chroot isolation may leak environment values to intermediate processes
Blast Radius
github.com/containers/buildah🐹github.com/containers/buildah🐹github.com/containers/buildah🐹github.com/containers/buildahReal-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
An information disclosure flaw was found in Buildah, when building containers using chroot isolation. Running processes in container builds (e.g. Dockerfile RUN commands) can access environment variables from parent and grandparent processes. When run in a container in a CI/CD environment, environment variables may include sensitive information that was shared with the container in order to be used only by Buildah itself (e.g. container registry credentials).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/containers/buildah | all versions | 1.16.8 |
| 🐹Go | github.com/containers/buildah | ≥ 1.17.0&&< 1.17.2 | 1.17.2 |
| 🐹Go | github.com/containers/buildah | ≥ 1.18.0&&< 1.19.9 | 1.19.9 |
| 🐹Go | github.com/containers/buildah | ≥ 1.20.0&&< 1.21.3 | 1.21.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containers/buildah. 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/containers/buildah to 1.16.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3602 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-2021-3602 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-2021-3602. 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-2021-3602 in your dependencies?
O3 detects CVE-2021-3602 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.