CVE-2023-25173: containerd supplementary groups are not set up properly
Impact
A bug was found in containerd where supplementary groups are not set up properly inside a container. If an attacker has direct access to a container and manipulates their supplementary group access, they may be able to use supplementary group access to bypass primary group restrictions in some cases, potentially gaining access to sensitive information or gaining the ability to execute code in that container.
Downstream applications that use the containerd client library may be affected as well.
Patches This bug has been fixed in containerd v1.6.18 and v.1.5.18. Users should update to these versions and recreate containers to resolve this issue. Users who rely on a downstream application that uses containerd's client library should check that application for a separate advisory and instructions.
Workarounds
Ensure that the "USER $USERNAME" Dockerfile instruction is not used. Instead, set the container entrypoint to a value similar to ENTRYPOINT ["su", "-", "user"] to allow su to properly set up supplementary groups.
References
- https://www.benthamsgaze.org/2022/08/22/vulnerability-in-linux-containers-investigation-and-mitigation/ - Docker/Moby: CVE-2022-36109, fixed in Docker 20.10.18 - CRI-O: CVE-2022-2995, fixed in CRI-O 1.25.0 - Podman: CVE-2022-2989, fixed in Podman 3.0.1 and 4.2.0 - Buildah: CVE-2022-2990, fixed in Buildah 1.27.1
Note that CVE IDs apply to a particular implementation, even if an issue is common.
For more information
If you have any questions or comments about this advisory:
Open an issue in containerd Email us at security@containerd.io
To report a security issue in containerd: Report a new vulnerability Email us at security@containerd.io
Other sources
containerd is an open source container runtime. A bug was found in containerd prior to versions 1.6.18 and 1.5.18 where supplementary groups are not set up properly inside a container. If an attacker has direct access to a container and manipulates their supplementary group access, they may be able to use supplementary group access to bypass primary group restrictions in some cases, potentially gaining access to sensitive information or gaining the ability to execute code in that container. Downstream applications that use the containerd client library may be affected as well.
This bug has been fixed in containerd v1.6.18 and v.1.5.18. Users should update to these versions and recreate containers to resolve this issue. Users who rely on a downstream application that uses containerd's client library should check that application for a separate advisory and instructions. As a workaround, ensure that the "USER $USERNAME" Dockerfile instruction is not used. Instead, set the container entrypoint to a value similar to ENTRYPOINT ["su", "-", "user"] to allow su to properly set up supplementary groups.
— NVD
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2023-25173?
CVE-2023-25173 is a vulnerability in containerd, an open source container runtime, where supplementary groups are not set up properly inside a container.
What is the impact of CVE-2023-25173?
The impact of CVE-2023-25173 is that if an attacker has direct access to a container and manipulates their supplementary group access, they may be able to bypass primary group restrictions.
How severe is CVE-2023-25173?
CVE-2023-25173 has a severity rating of 7.8 (High).
Which software versions are affected by CVE-2023-25173?
Containerd versions up to and excluding 1.5.18 as well as versions up to and excluding 1.6.18 are affected by CVE-2023-25173.
Where can I find more information about CVE-2023-25173?
More information about CVE-2023-25173 can be found at the following references: [GitHub Advisory](https://github.com/containerd/containerd/security/advisories/GHSA-hmfx-3pcx-653p), [Moby Advisory](https://github.com/moby/moby/security/advisories/GHSA-rc4r-wh2q-q6c4), [NVD](https://nvd.nist.gov/vuln/detail/CVE-2023-25173).