GHSA-7638-r9r3-rmjj
MEDIUMGHSA-7638-r9r3-rmjj is a medium-severity (CVSS 5.5) Information Exposure vulnerability in github.com/containers/buildah. O3 Security confirms whether GHSA-7638-r9r3-rmjj 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
Impact
When running processes using "chroot" isolation, the process being run can examine the environment variables of its immediate parent and grandparent processes (CVE-2021-3602). This isolation type is often used when running buildah in unprivileged containers, and it is often used to do so in CI/CD environments. If sensitive information is exposed to the original buildah process through its environment, that information will unintentionally be shared with child processes which it starts as part of handling RUN instructions or during buildah run. The commands that buildah is instructed to run can read that information if they choose to.
Patches
Users should upgrade packages, or images which contain packages, to include version 1.21.3 or later.
Workarounds
As a workaround, invoking buildah in a container under env -i to have it started with a reinitialized environment should prevent the leakage.
For more information
If you have any questions or comments about this advisory:
- Open an issue in buildah
- Email us at the buildah general mailing list, or the podman security mailing list if it's sensitive.
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 GHSA-7638-r9r3-rmjj 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-7638-r9r3-rmjj 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-7638-r9r3-rmjj. 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-7638-r9r3-rmjj in your dependencies?
O3 detects GHSA-7638-r9r3-rmjj across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.