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OpenAdvisories
High USN-4960-1 1 CVE

runc vulnerability

Published May 19, 2021 · Updated Feb 10, 2026

Ecosystem: Ubuntu

Summary

Etienne Champetier discovered that runC incorrectly checked mount targets.
An attacker with a malicious container image could possibly mount the host
filesystem into the container and escalate privileges.

Fixed packages 2

ReleasePackageFixed in
Ubuntu · 18.04 LTS 18.04:LTS runc 1.0.0~rc93-0ubuntu1~18.04.2
Ubuntu · 20.04 LTS 20.04:LTS runc 1.0.0~rc93-0ubuntu1~20.04.2

Vulnerabilities 1

  • High 7.6
    CVE-2021-30465 EPSS 10%

    mount destinations can be swapped via symlink-exchange to cause mounts outside the rootfs

    runc before 1.0.0-rc95 allows a Container Filesystem Breakout via Directory Traversal. To exploit the vulnerability, an attacker must be able to create multiple containers with a fairly specific mount configuration. The problem occurs via a symlink-exchange a…

    buildah runc github.com/opencontainers/runc k3s Debian Ubuntu Azure Linux Alpine Go

References

  • report
    https://ubuntu.com/security/CVE-2021-30465