Vulnerability Description
In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-remap", if the root user in the remapped namespace has access to the host filesystem they can modify files under "/var/lib/docker/<remapping>" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Docker | Docker | < 19.03.15 |
| Debian | Debian Linux | 10.0 |
| Netapp | E-Series Santricity Os Controller | >= 11.0.0, <= 11.60.3 |
Related Weaknesses (CWE)
References
- https://docs.docker.com/engine/release-notes/#20103Release NotesVendor Advisory
- https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7cPatchThird Party Advisory
- https://github.com/moby/moby/releases/tag/v19.03.15Release NotesThird Party Advisory
- https://github.com/moby/moby/releases/tag/v20.10.3Release NotesThird Party Advisory
- https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpcThird Party Advisory
- https://security.gentoo.org/glsa/202107-23PatchThird Party Advisory
- https://security.netapp.com/advisory/ntap-20210226-0005/Third Party Advisory
- https://www.debian.org/security/2021/dsa-4865Third Party Advisory
- https://docs.docker.com/engine/release-notes/#20103Release NotesVendor Advisory
- https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7cPatchThird Party Advisory
- https://github.com/moby/moby/releases/tag/v19.03.15Release NotesThird Party Advisory
- https://github.com/moby/moby/releases/tag/v20.10.3Release NotesThird Party Advisory
- https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpcThird Party Advisory
- https://security.gentoo.org/glsa/202107-23PatchThird Party Advisory
- https://security.netapp.com/advisory/ntap-20210226-0005/Third Party Advisory
FAQ
What is CVE-2021-21284?
CVE-2021-21284 is a vulnerability with a CVSS score of 6.8 (MEDIUM). In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-...
How severe is CVE-2021-21284?
CVE-2021-21284 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-21284?
Check the references section above for vendor advisories and patch information. Affected products include: Docker Docker, Debian Debian Linux, Netapp E-Series Santricity Os Controller.