CVE catalog
CVE-2021-41091
docker.io: CVE-2021-41091
- Severity
- Medium · CVSS 6.3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 2.85% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | docker.io | sid | 28.5.2+dfsg4-5 | fixed |
| Debian | docker.io | forky | 28.5.2+dfsg4-5 | fixed |
| Debian | docker.io | trixie | 26.1.5+dfsg1-9+deb13u1 | fixed |
| Debian | docker.io | trixie-security | 26.1.5+dfsg1-9+deb13u1 | fixed |
| Debian | docker.io | bookworm | 20.10.24+dfsg1-1+deb12u1 | fixed |
| Ubuntu | docker.io | 18.04 | 1.13.1-0ubuntu6 | vulnerable |
| Ubuntu | docker.io | 18.04 | 17.03.2-0ubuntu1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 17.03.2-0ubuntu3 | vulnerable |
| Ubuntu | docker.io | 18.04 | 17.03.2-0ubuntu5 | vulnerable |
| Ubuntu | docker.io | 18.04 | 17.12.1-0ubuntu1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 18.06.1-0ubuntu1~18.04.1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 18.06.1-0ubuntu1.2~18.04.1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 18.09.2-0ubuntu1~18.04.1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 18.09.5-0ubuntu1~18.04.2 | vulnerable |
| Ubuntu | docker.io | 18.04 | 18.09.7-0ubuntu1~18.04.1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 18.09.7-0ubuntu1~18.04.3 | vulnerable |
| Ubuntu | docker.io | 18.04 | 18.09.7-0ubuntu1~18.04.4 | vulnerable |
| Ubuntu | docker.io | 18.04 | 19.03.6-0ubuntu1~18.04.1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 19.03.6-0ubuntu1~18.04.2 | vulnerable |
| Ubuntu | docker.io | 18.04 | 19.03.6-0ubuntu1~18.04.3 | vulnerable |
| Ubuntu | docker.io | 18.04 | 20.10.2-0ubuntu1~18.04.2 | vulnerable |
| Ubuntu | docker.io | 18.04 | 20.10.2-0ubuntu1~18.04.3 | vulnerable |
| Ubuntu | docker.io | 18.04 | 20.10.7-0ubuntu1~18.04.1 | vulnerable |
| Ubuntu | docker.io | 18.04 | 20.10.7-0ubuntu1~18.04.2 | vulnerable |
| Ubuntu | docker.io | 18.04 | 20.10.7-0ubuntu5~18.04.2 | fixed |
| Ubuntu | docker.io | 20.04 | 19.03.2-0ubuntu1 | vulnerable |
| Ubuntu | docker.io | 20.04 | 19.03.6-0ubuntu1 | vulnerable |
| Ubuntu | docker.io | 20.04 | 19.03.8-0ubuntu1 | vulnerable |
| Ubuntu | docker.io | 20.04 | 19.03.8-0ubuntu1.20.04 | vulnerable |
| Ubuntu | docker.io | 20.04 | 19.03.8-0ubuntu1.20.04.1 | vulnerable |
| Ubuntu | docker.io | 20.04 | 19.03.8-0ubuntu1.20.04.2 | vulnerable |
| Ubuntu | docker.io | 20.04 | 20.10.2-0ubuntu1~20.04.2 | vulnerable |
| Ubuntu | docker.io | 20.04 | 20.10.2-0ubuntu1~20.04.3 | vulnerable |
| Ubuntu | docker.io | 20.04 | 20.10.7-0ubuntu1~20.04.1 | vulnerable |
| Ubuntu | docker.io | 20.04 | 20.10.7-0ubuntu1~20.04.2 | vulnerable |
| Ubuntu | docker.io | 20.04 | 20.10.7-0ubuntu5~20.04.1 | fixed |
| Ubuntu | docker.io | 22.04 | 20.10.7-0ubuntu5 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | docker.io | source | sid | 20.10.10+dfsg1-1 | not yet assigned | Not reported | Not reported |
| Debian | docker.io | source | forky | 20.10.10+dfsg1-1 | not yet assigned | Not reported | Not reported |
| Debian | docker.io | source | trixie | 20.10.10+dfsg1-1 | not yet assigned | Not reported | Not reported |
| Debian | docker.io | source | bookworm | 20.10.10+dfsg1-1 | not yet assigned | Not reported | Not reported |
| Ubuntu | docker.io | deb | 18.04 | 20.10.7-0ubuntu5~18.04.2 | Not reported | UBUNTU-CVE-2021-41091 | Not reported |
| Ubuntu | docker.io | deb | 20.04 | 20.10.7-0ubuntu5~20.04.1 | Not reported | UBUNTU-CVE-2021-41091 | Not reported |
| Ubuntu | docker.io | deb | 22.04 | 20.10.7-0ubuntu5 | Not reported | UBUNTU-CVE-2021-41091 | Not reported |
OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.
[Debian 12 (Bookworm)]
- [docker-doc]Unknown
Source package: [docker.io]
Details (2)
20.10.24+dfsg1-1+deb12u1· all · bookwormFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · bookworm; dsa · docker.io · debian · 12
20.10.24+dfsg1-1+deb12u1· all · bookwormFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · bookworm; dsa · docker.io · debian · 12
- [docker.io]Unknown
Source package: [docker.io]
Details (2)
20.10.24+dfsg1-1+deb12u1+b6· amd64 · bookwormFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · bookworm; dsa · docker.io · debian · 12
20.10.24+dfsg1-1+deb12u1+b6· arm64 · bookwormFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · bookworm; dsa · docker.io · debian · 12
- [golang-github-docker-docker-dev]Unknown
Source package: [docker.io]
Details (2)
20.10.24+dfsg1-1+deb12u1· all · bookwormFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · bookworm; dsa · docker.io · debian · 12
20.10.24+dfsg1-1+deb12u1· all · bookwormFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · bookworm; dsa · docker.io · debian · 12
[Debian 13 (Trixie)]
- [docker-cli]Unknown
Source package: [docker.io]
Details (4)
26.1.5+dfsg1-9+b13· amd64 · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+b13· arm64 · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· amd64 · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· arm64 · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
- [docker-doc]Unknown
Source package: [docker.io]
Details (4)
26.1.5+dfsg1-9· all · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9· all · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· all · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· all · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
- [docker.io]Unknown
Details (4)
26.1.5+dfsg1-9+b13· amd64 · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+b13· arm64 · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· amd64 · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· arm64 · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
- [golang-github-docker-docker-dev]Unknown
Source package: [docker.io]
Details (4)
26.1.5+dfsg1-9· all · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9· all · trixieFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· all · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
26.1.5+dfsg1-9+deb13u1· all · trixie-securityFixed · Fixed:
20.10.10+dfsg1-1dsa · docker.io · debian · 13
Observed:
References
- [https://cert-portal.siemens.com/productcert/csaf/ssa-222547.json]
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2021_3336-1.json]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2021-41091]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2021-41091]
- [https://security-tracker.debian.org/tracker/CVE-2021-41091]
- [https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-41091.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2021/wid-sec-w-2023-1124.json]
[CERT-Bund public advisories] · [CISA cybersecurity advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]