CVE-2021-21284
MEDIUM severity · CVSS 6.8 · Path traversal
6.8CVSS MEDIUM
Summary
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.
Impact & exploitability
Attack vectorAdjacent
Attack complexityLow
Privileges requiredLow
User interactionNone
Confidentiality impactNone
Integrity impactHigh
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
Affected products we track (1)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.
Official patch: https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7c ↗
Additional information
- NVD record
- https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7cPatch
- https://security.gentoo.org/glsa/202107-23Patch
- https://docs.docker.com/engine/release-notes/#20103Advisory
- https://github.com/moby/moby/releases/tag/v19.03.15Advisory
- https://github.com/moby/moby/releases/tag/v20.10.3Advisory
- https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpcAdvisory
- https://security.netapp.com/advisory/ntap-20210226-0005/Advisory
- https://www.debian.org/security/2021/dsa-4865Advisory