CVE Vulnerability

CVE-2021-43784

runc is a CLI tool for spawning and running containers on Linux according to the OCI specification. In runc, netlink is used internally as a serialization system for specifying the relevant container configuration to the `C` portion of the code (responsible for the based namespace setup of containers). In all versions of runc prior to 1.0.3, the encoder did not handle the possibility of an integer overflow in the 16-bit length field for the byte array attribute type, meaning that a large enough malicious byte array attribute could result in the length overflowing and the attribute contents being parsed as netlink messages for container configuration. This vulnerability requires the attacker to have some control over the configuration of the container and would allow the attacker to bypass the namespace restrictions of the container by simply adding their own netlink payload which disables all namespaces. The main users impacted are those who allow untrusted images with untrusted configurations to run on their machines (such as with shared cloud infrastructure). runc version 1.0.3 contains a fix for this bug. As a workaround, one may try disallowing untrusted namespace paths from your container. It should be noted that untrusted namespace paths would allow the attacker to disable namespace protections entirely even in the absence of this bug.

6 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 6.8 / Impact : 6.4

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

Scope

5 /10

CVSS v3.0 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.6 / Impact : 3.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References
Link Resource
https://github.com/opencontainers/runc/commit/d72d057ba794164c3cce9451a00b72a78b25e1ae Patch Third Party Advisory
https://github.com/opencontainers/runc/commit/9c444070ec7bb83995dbc0185da68284da71c554 Patch Third Party Advisory
https://github.com/opencontainers/runc/commit/f50369af4b571e358f20b139eea52d612eb55eed Patch Third Party Advisory
https://github.com/opencontainers/runc/security/advisories/GHSA-v95c-p5hm-xq8f Patch Third Party Advisory
https://bugs.chromium.org/p/project-zero/issues/detail?id=2241 Exploit Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/12/msg00005.html Vendor Advisory
Configurations

Configuration 1

cpe:2.3:a:linuxfoundation:runc:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
Information

Published : 2021-12-06 06:15

Updated : 2021-12-08 06:05

NVD link : CVE-2021-43784

Mitre link : CVE-2021-43784

Products Affected
No products.
CWE
CWE-190