GHSA-2mm7-x5h6-5pvq

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Source
https://github.com/advisories/GHSA-2mm7-x5h6-5pvq
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/04/GHSA-2mm7-x5h6-5pvq/GHSA-2mm7-x5h6-5pvq.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-2mm7-x5h6-5pvq
Aliases
Related
Published
2024-04-22T18:45:21Z
Modified
2024-04-22T18:45:21Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L CVSS Calculator
Summary
Moby (Docker Engine) started with non-empty inheritable Linux process capabilities
Details

Impact

A bug was found in Moby (Docker Engine) where containers were incorrectly started with non-empty inheritable Linux process capabilities, creating an atypical Linux environment and enabling programs with inheritable file capabilities to elevate those capabilities to the permitted set during execve(2). Normally, when executable programs have specified permitted file capabilities, otherwise unprivileged users and processes can execute those programs and gain the specified file capabilities up to the bounding set. Due to this bug, containers which included executable programs with inheritable file capabilities allowed otherwise unprivileged users and processes to additionally gain these inheritable file capabilities up to the container's bounding set. Containers which use Linux users and groups to perform privilege separation inside the container are most directly impacted.

This bug did not affect the container security sandbox as the inheritable set never contained more capabilities than were included in the container's bounding set.

Patches

This bug has been fixed in Moby (Docker Engine) 20.10.14. Users should update to this version as soon as possible. Running containers should be stopped, deleted, and recreated for the inheritable capabilities to be reset.

This fix changes Moby (Docker Engine) behavior such that containers are started with a more typical Linux environment. Refer to capabilities(7) for a description of how capabilities work. Note that permitted file capabilities continue to allow for privileges to be raised up to the container's bounding set and that processes may add capabilities to their own inheritable set up to the container's bounding set per the rules described in the manual page. In all cases the container's bounding set provides an upper bound on the capabilities that can be assumed and provides for the container security sandbox.

Workarounds

The entrypoint of a container can be modified to use a utility like capsh(1) to drop inheritable capabilities prior to the primary process starting.

Credits

The Moby project would like to thank Andrew G. Morgan for responsibly disclosing this issue in accordance with the Moby security policy.

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
View open source insights on deps.dev
Purl
pkg:golang/github.com/moby/moby

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
20.10.14

Go / github.com/docker/docker

Package

Name
github.com/docker/docker
View open source insights on deps.dev
Purl
pkg:golang/github.com/docker/docker

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
20.10.14