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 attack that relies on a race condition.

Affected: Ubuntu:Pro:16.04:LTS: runc

It was discovered that runC incorrectly checked mount targets. An attacker with a malicious container image could possibly mount over the /proc directory and escalate privileges. (CVE-2019-16884)

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. (CVE-2021-30465)