CVE-2021-21284 Information

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/\ 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 Vector

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

Reference

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

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

NONE

Availability Impact

HIGH

Base Score

NONE

Base Severity

6.8