GHSA-rc4r-wh2q-q6c4

Source
https://github.com/advisories/GHSA-rc4r-wh2q-q6c4
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/09/GHSA-rc4r-wh2q-q6c4/GHSA-rc4r-wh2q-q6c4.json
Aliases
Related
Published
2022-09-16T21:00:46Z
Modified
2023-11-08T04:09:15.359127Z
Details

Moby is an open-source project created by Docker to enable software containerization. A bug was found in Moby (Docker Engine) where supplementary groups are not set up properly. 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. This bug is fixed in Moby (Docker Engine) 20.10.18. Users should update to this version when it is available. Running containers should be stopped and restarted for the permissions to be fixed. For users unable to upgrade, this problem can be worked around by not using the "USER $USERNAME" Dockerfile instruction. Instead by calling ENTRYPOINT ["su", "-", "user"] the supplementary groups will be set up properly.

Thanks to Steven Murdoch for reporting this issue.

Impact

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.

Patches

This bug is fixed in Moby (Docker Engine) 20.10.18. Users should update to this version when it is available.

Workarounds

This problem can be worked around by not using the "USER $USERNAME" Dockerfile instruction. Instead by calling ENTRYPOINT ["su", "-", "user"] the supplementary groups will be set up properly.

References

https://www.benthamsgaze.org/2022/08/22/vulnerability-in-linux-containers-investigation-and-mitigation/

For more information

If you have any questions or comments about this advisory:

References

Affected packages

Go / github.com/moby/moby

Package

Name
github.com/moby/moby

Affected ranges

Type
SEMVER
Events
Introduced
0The exact introduced commit is unknown
Fixed
20.10.18