How severe is CVE-2021-3602?

CVE-2021-3602 has a CVSS score of 5.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-3602?

CVE-2021-3602 affects the following packages: github.com/containers/buildah (Go), github.com/containers/buildah (Go), github.com/containers/buildah (Go), github.com/containers/buildah (Go). Ecosystems affected: Go.

How do I fix CVE-2021-3602?

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.

How do I detect CVE-2021-3602 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containers/buildah, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-3602 if there is no patch (or I can't update yet)?

Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.

Is CVE-2021-3602 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-3602 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-3602?

CVE-2021-3602 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 26th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-3602?

CVE-2021-3602 is classified as Information Exposure (CWE-200), CWE-212 (CWE-212). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-3602 published, and has it been updated?

CVE-2021-3602 was published on March 3, 2022 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

MEDIUM severity

CVE-2021-3602 — buildah

MEDIUMFix: containers/buildah@a468ce0

CVE-2021-3602 is a medium-severity (CVSS 5.5) Information Exposure vulnerability in github.com/containers/buildah. A fix is available for github.com/containers/buildah — see the affected versions and patch details below.

Buildah processes using chroot isolation may leak environment values to intermediate processes

Also known asGHSA-7638-r9r3-rmjjGO-2022-0345

Published

Mar 3, 2022

Updated

Oct 20, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs26th percentile — riskier than 26% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected

🐹github.com/containers/buildah🐹github.com/containers/buildah🐹github.com/containers/buildah🐹github.com/containers/buildah

Real-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

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/containers/buildah`	all versions	1.16.8`go get github.com/containers/buildah@v1.16.8`
🐹Go	`github.com/containers/buildah`	≥ 1.17.0&&< 1.17.2	1.17.2`go get github.com/containers/buildah@v1.17.2`
🐹Go	`github.com/containers/buildah`	≥ 1.18.0&&< 1.19.9	1.19.9`go get github.com/containers/buildah@v1.19.9`
🐹Go	`github.com/containers/buildah`	≥ 1.20.0&&< 1.21.3	1.21.3`go get github.com/containers/buildah@v1.21.3`

Affected Products

4 products · 7 configurations

Application

buildahbuildah_project

≥ 1.21.0 && < 1.21.3

range

enterprise linuxredhat

1 version

8.0

enterprise linux for ibm z systemsredhat

1 version

8.0

enterprise linux for power little endianredhat

1 version

8.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containers/buildah, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.

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.

Red HatModerate

OpenShift Container Platform 4's builder container is not vulnerable to this flaw as it uses OCI isolation (i.e. using runc) and does not use chroot isolation.

Product	Fixed in	Advisory
Red Hat Enterprise Linux 8	`container-tools:rhel8-8050020210921082437.faa19cc5`	RHSA-2021:4154
Red Hat Enterprise Linux 8	`container-tools:2.0-8050020210817115648.faa19cc5`	RHSA-2021:4221
Red Hat Enterprise Linux 8	`container-tools:3.0-8050020210915114620.faa19cc5`	RHSA-2021:4222

Frequently Asked Questions

### 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