CVE-2021-41091
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…
Does this matter?
Lower severity and a low EPSS score (2.85%). Track it; it rarely justifies an emergency change on its own.
Description
Moby is an open-source project created by Docker to enable software containerization. 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. This bug has been fixed in Moby (Docker Engine) 20.10.9. Users should update to this version 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.
- CVSS 3.1
- 6.3 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
- EPSS
- 2.85% probability · 86th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-281, CWE-732
- Affected
- mobyproject/moby · fedoraproject/fedora
- Source
- security-advisories@github.com
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
- https://github.com/moby/moby/commit/f0ab919f518c47240ea0e72d0999576bb8008e64Patch, Third Party Advisory
- https://github.com/moby/moby/security/advisories/GHSA-3fwx-pjgw-3558Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B5Q6G6I4W5COQE25QMC7FJY3I3PAYFBB/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNFADTCHHYWVM6W4NJ6CB4FNFM2VMBIB/
- https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
- https://github.com/moby/moby/commit/f0ab919f518c47240ea0e72d0999576bb8008e64Patch, Third Party Advisory
- https://github.com/moby/moby/security/advisories/GHSA-3fwx-pjgw-3558Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B5Q6G6I4W5COQE25QMC7FJY3I3PAYFBB/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNFADTCHHYWVM6W4NJ6CB4FNFM2VMBIB/
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.