Vulnerability Report

CVE-2021-21284

Title: Docker Privilege Escalation via --userns-remap

Privilege Escalation

Proof Of Concept

No public PoC currently indexed for CVE-2021-21284.

CWE Category CWE-22
Published Date Feb 02, 2021
Modified Date Nov 21, 2024
Exploit Status Not Found
Score 6.8 CVSS v3.1
Exploit Probability (EPSS)
0.02%

Vulnerability Summary

CVE-2021-21284: 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.

Impacted Vendors

D
docker 1
R
redhat 1
N
netapp 1
S
synology 1

Reference Links

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 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
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.8
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.8
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
CVSS v2.0
Source Entity [email protected]
Severity LOW
2.7
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:A/AC:L/Au:S/C:N/I:P/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-21284 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector ADJACENT_NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N

Affected Stack

No specific products linked.