Libcontainer 1.6.0, as used in Docker Engine, allows local users to escape containerization ("mount namespace breakout") and write to arbitrary file on the host system via a symlink attack in an image when respawning a container.

Docker Engine before 1.6.1 uses weak permissions for (1) /proc/asound, (2) /proc/timer_stats, (3) /proc/latency_stats, and (4) /proc/fs, which allows local users to modify the host, obtain sensitive information, and perform protocol downgrade attacks

Libcontainer and Docker Engine before 1.6.1 opens the file-descriptor passed to the pid-1 process before performing the chroot, which allows local users to gain privileges via a symlink attack in an image.

Docker Engine before 1.6.1 allows local users to set arbitrary Linux Security Modules (LSM) and docker_t policies via an image that allows volumes to override files in /proc.