Vulnerability · Published Feb 2, 2021 · Assigned by GitHub_M
CVE-2021-21284privilege escalation in Moby
Medium 6.8
In plain English
A medium-severity path traversal in moby from moby. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | docker | 20.10.3-r0 | ALPINE-CVE-2021-21284 |
| Alpine:v3.21 | docker | 20.10.3-r0 | ALPINE-CVE-2021-21284 |
| Alpine:v3.22 | docker | 20.10.3-r0 | ALPINE-CVE-2021-21284 |
| Alpine:v3.23 | docker | 20.10.3-r0 | ALPINE-CVE-2021-21284 |
| Alpine:v3.24 | docker | 20.10.3-r0 | ALPINE-CVE-2021-21284 |
| Debian:12 | docker.io | 20.10.3+dfsg1-1 | DEBIAN-CVE-2021-21284 |
| Debian:13 | docker.io | 20.10.3+dfsg1-1 | DEBIAN-CVE-2021-21284 |
| Debian:14 | docker.io | 20.10.3+dfsg1-1 | DEBIAN-CVE-2021-21284 |
| Go | github.com/moby/moby | 20.10.3 | GHSA-7452-xqpj-6rpc |
| Go | github.com/moby/moby | 19.3.15 | GHSA-7452-xqpj-6rpc |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
References
- https://docs.docker.com/engine/release-notes/#20103 x_refsource_MISC
- https://github.com/moby/moby/releases/tag/v20.10.3 x_refsource_MISC
- https://github.com/moby/moby/releases/tag/v19.03.15 x_refsource_MISC
- https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpc x_refsource_CONFIRM
- https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7c x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20210226-0005/ x_refsource_CONFIRM
- DSA-4865 vendor-advisory, x_refsource_DEBIAN
- GLSA-202107-23 vendor-advisory, x_refsource_GENTOO