CVE-2021-41089 `docker cp` allows unexpected chmod of host files
Attackers can use docker cp to modify host file permissions, potentially widening access to sensitive files on the host system.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-41089?
CVE-2021-41089 is a low-severity vulnerability in Fedoraproject Fedora, published on 4 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Moby is an open-source project created by Docker to enable software containerization. A bug was found in Moby (Docker Engine) where attempting to copy files using `docker cp` into a specially-crafted container can result in Unix file permission changes for existing files in the host’s filesystem, widening access to others. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process. This bug has been fixed in Moby (Docker Engine) 20.10.9. Users should update to this version as soon as possible. Running containers do not need to be restarted.
Weakness: CWE-281
Which versions are affected by CVE-2021-41089?
4 open source packages ship an affected version, including github.com/docker/docker and github.com/moby/moby. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
github.com/docker/docker Go | All versions | 20.10.9 |
github.com/docker/docker Go | All versions | 20.10.9 |
github.com/docker/docker Go | All versions | 20.10.9+incompatible |
github.com/moby/moby Go | All versions | 20.10.9+incompatible |
Linux distribution packages (1)
docker openSUSE:Tumbleweed | All versions | 20.10.9_ce-1.2 |
Products include Fedoraproject Fedora, Mobyproject Moby.
How do I fix CVE-2021-41089?
Upgrade github.com/docker/docker to a fixed version for your release line: 20.10.9 or 20.10.9+incompatible.
Is CVE-2021-41089 being exploited?
There is no known exploitation of CVE-2021-41089 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as CLEANSTART-2026-HF26870, DEBIAN-CVE-2021-41089, GHSA-v994-f8vw-g7j4, GO-2024-2913, UBUNTU-CVE-2021-41089, USN-5103-1 and 1 more.