CVE-2021-21284
Vulnerability Summary
Timeline
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 Metrics
- v3.1•MEDIUM•Score: 6.8CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
- v2.0•LOW•Score: 2.7AV:A/AC:L/Au:S/C:N/I:P/A:N
EPSS Trends
Current EPSS score: 0.02%• Percentile: 6%
Techniques & Countermeasures
- CWE-22•Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Affected Systems
- debian•debian_linux
10.0
- docker•docker
< 19.03.15 | ≥ 20.0.0, < 20.10.3
- github.com/moby•moby
< 19.3.15 | ≥ 20.10.0-beta1, < 20.10.3
- moby•moby
< 19.03.15 | ≥ 20.0.0, < 20.10.3
- netapp•e-series_santricity_os_controller
≥ 11.0.0, ≤ 11.60.3
References (10)
- https://docs.docker.com/engine/release-notes/#20103
- https://github.com/moby/moby/releases/tag/v20.10.3
- https://github.com/moby/moby/releases/tag/v19.03.15
- https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpc
- https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7c
- https://security.netapp.com/advisory/ntap-20210226-0005/
- https://www.debian.org/security/2021/dsa-4865
- https://security.gentoo.org/glsa/202107-23
- https://nvd.nist.gov/vuln/detail/CVE-2021-21284
- https://security.netapp.com/advisory/ntap-20210226-0005