CVE-2021-21284
Published: August 31, 2023Last modified: August 31, 2023
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.8 |
| Attack Vector | ADJACENT_NETWORK |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | CHANGED |
| Confidentiality | NONE |
| Integrity impact | HIGH |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | docker | Not affected (20.10.24-r2) |
| Stream | docker | Not affected (24.0.5-r1) |
References
- https://docs.docker.com/engine/release-notes/#20103
- https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7c
- https://github.com/moby/moby/releases/tag/v19.03.15
- https://github.com/moby/moby/releases/tag/v20.10.3
- https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpc
- https://security.gentoo.org/glsa/202107-23
- https://security.netapp.com/advisory/ntap-20210226-0005/
- https://www.debian.org/security/2021/dsa-4865