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.
Advisories
Source ID Title
Debian DSA Debian DSA DSA-4865-1 docker.io security update
EUVD EUVD EUVD-2024-0280 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.
Github GHSA Github GHSA GHSA-7452-xqpj-6rpc moby Access to remapped root allows privilege escalation to real root
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2024-08-03T18:09:15.042Z

Reserved: 2020-12-22T00:00:00

Link: CVE-2021-21284

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-02-02T18:15:11.827

Modified: 2024-11-21T05:47:55.867

Link: CVE-2021-21284

cve-icon Redhat

Severity : Moderate

Publid Date: 2021-02-02T00:00:00Z

Links: CVE-2021-21284 - Bugzilla

cve-icon OpenCVE Enrichment

No data.