PT-2021-7961 · Docker+2 · Moby+3
Joan Bruguera
·
Published
2021-09-09
·
Updated
2025-10-13
·
CVE-2021-41091
CVSS v3.1
6.3
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L |
Name of the Vulnerable Software and Affected Versions
Moby (Docker Engine) versions prior to 20.10.9
Description
A bug was found in Moby (Docker Engine) where the data directory (typically
/var/lib/docker) contained subdirectories with insufficiently restricted permissions, allowing otherwise unprivileged Linux users to traverse directory contents and execute programs. When containers included executable programs with extended permission bits (such as setuid), unprivileged Linux users could discover and execute those programs. When the UID of an unprivileged Linux user on the host collided with the file owner or group inside a container, the unprivileged Linux user on the host could discover, read, and modify those files.Recommendations
For Moby (Docker Engine) versions prior to 20.10.9, update to version 20.10.9 as soon as possible.
Running containers should be stopped and restarted for the permissions to be fixed.
For users unable to upgrade, limit access to the host to trusted users.
Limit access to host volumes to trusted containers.
Exploit
Fix
Incorrect Permission
Improper Preservation of Permissions
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Related Identifiers
Affected Products
Astra Linux
Docker
Moby
Suse