CVE-2021-21284

Name
CVE-2021-21284
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.
NVD Severity
medium
Other trackers
CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia
Mailing lists
oss-security, full-disclosure, bugtraq
Exploits
Exploit DB, Metasploit
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
Patch https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7c
Release Notes https://docs.docker.com/engine/release-notes/#20103
Third Party Advisory https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpc
Release Notes https://github.com/moby/moby/releases/tag/v19.03.15
Release Notes https://github.com/moby/moby/releases/tag/v20.10.3
Third Party Advisory https://security.netapp.com/advisory/ntap-20210226-0005/
Third Party Advisory https://www.debian.org/security/2021/dsa-4865
GENTOO https://security.gentoo.org/glsa/202107-23

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:docker:docker:*:*:*:*:*:*:*:* docker >= None < 19.03.15
cpe:2.3:a:docker:docker:*:*:*:*:*:*:*:* docker >= 20.0.0 < 20.10.3

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
docker edge-community 20.10.3-r0 None fixed
docker edge-community 19.03.14-r0 None possibly vulnerable
docker edge-community 19.03.11-r0 None possibly vulnerable
docker edge-community 19.03.1-r0 None possibly vulnerable
docker edge-community 18.09.8-r0 None possibly vulnerable
docker edge-community 18.09.7-r0 None possibly vulnerable
docker 3.22-community 20.10.3-r0 None fixed
docker 3.21-community 20.10.3-r0 None fixed
docker 3.20-community 20.10.3-r0 None fixed
docker 3.19-community 20.10.3-r0 None fixed
docker 3.18-community 20.10.3-r0 None fixed
docker 3.17-community 20.10.3-r0 None fixed