CVE-2021-21284

medium

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.

References

https://github.com/moby/moby/commit/64bd4485b3a66a597c02c95f5776395e540b2c7c

https://docs.docker.com/engine/release-notes/#20103

https://github.com/moby/moby/security/advisories/GHSA-7452-xqpj-6rpc

https://github.com/moby/moby/releases/tag/v19.03.15

https://github.com/moby/moby/releases/tag/v20.10.3

https://security.netapp.com/advisory/ntap-20210226-0005/

https://www.debian.org/security/2021/dsa-4865

https://security.gentoo.org/glsa/202107-23

Details

Source: MITRE

Published: 2021-02-02

Updated: 2022-04-29

Type: CWE-22

Risk Information

CVSS v2

Base Score: 2.7

Vector: AV:A/AC:L/Au:S/C:N/I:P/A:N

Impact Score: 2.9

Exploitability Score: 5.1

Severity: LOW

CVSS v3

Base Score: 6.8

Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N

Impact Score: 4

Exploitability Score: 2.3

Severity: MEDIUM