GHSA-rc4r-wh2q-q6c4

    Dashboard / Vulnerabilities / GHSA-rc4r-wh2q-q6c4

    GHSA-rc4r-wh2q-q6c4

    Published: 16 Sept 2022Last Modified: 4 Feb 2026

    Summary: Docker supplementary group permissions not set up properly, allowing attackers to bypass primary group restrictions

    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: * [Open an issue](https://github.com/moby/moby/issues/new) * Email us at [[email protected]](mailto:[email protected])

    Affected packages

    Package

    Name: github.com/docker/docker

    Purl: pkg:golang/github.com/docker/docker

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 0
    Fixed -20.10.18

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    GHSA-rc4r-wh2q-q6c4 | CVE-DB