CVE-2021-32760

Archive package allows chmod of file outside of unpack target directory

Workarounds

Ensure you only pull images from trusted sources.

Linux security modules (LSMs) like SELinux and AppArmor can limit the files potentially affected by this bug through policies and profiles that prevent containerd from interacting with unexpected files.

For more information

If you have any questions or comments about this advisory:

• Open an issue
• Email us at [email protected] if you think you’ve found a security bug.

A bug was found in containerd where pulling and extracting a specially-crafted container image can result in Unix file permission changes for existing files in the host’s filesystem. Changes to file permissions can deny access to the expected owner of the file, widen access to others, or set extended bits like setuid, setgid, and sticky. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process.

A file, directory, or other resource is assigned permissions that allow broader access than intended. Typical impact: unauthorized read, modification, or execution of the resource.

CVE-2021-32760 has a CVSS score of 5.0 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.4.8, 1.5.4); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

This bug has been fixed in containerd 1.5.4 and 1.4.8. Users should update to these versions as soon as they are released. Running containers do not need to be restarted.

1. What is CVE-2021-32760? CVE-2021-32760 is a medium-severity incorrect permission assignment for critical resource vulnerability in github.com/containerd/containerd (go), affecting versions < 1.4.8. It is fixed in 1.4.8, 1.5.4. A file, directory, or other resource is assigned permissions that allow broader access than intended.
2. How severe is CVE-2021-32760? CVE-2021-32760 has a CVSS score of 5.0 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/containerd/containerd are affected by CVE-2021-32760? github.com/containerd/containerd (go) versions < 1.4.8 is affected.
4. Is there a fix for CVE-2021-32760? Yes. CVE-2021-32760 is fixed in 1.4.8, 1.5.4. Upgrade to this version or later.
5. Is CVE-2021-32760 exploitable, and should I be worried? Whether CVE-2021-32760 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2021-32760 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2021-32760?
   • Upgrade github.com/containerd/containerd to 1.4.8 or later
   • Upgrade github.com/containerd/containerd to 1.5.4 or later

Other vulnerabilities in github.com/containerd/containerd