CVE-2021-437846.0MediumCWE-190

CVE-2021-43784: Overflow in netlink bytemsg length field allows attacker to override netlink-based container configuration

opencontainers · runc

Affected: opencontainers runc · Exploitation: possible (1 to 10%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

1.8%probability of exploitation in the next 30 days

78th percentile

050100

Higher than 78% of scored CVEs

6.0MediumCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

opencontainers · runc< 1.0.3

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Possible (1 to 10%). EPSS between 1% and 10%.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Integer Overflow · Memory Corruption
Vendor: opencontainers
Published: December 2021
Band: Possible (1 to 10%), December 2021

CoverageNo articles yet

No CyberSIXT article names CVE-2021-43784 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.