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.
lists.opensuse.org/opensuse-updates/2015-05/msg00023.html
packetstormsecurity.com/files/131835/Docker-Privilege-Escalation-Information-Disclosure.html
seclists.org/fulldisclosure/2015/May/28
www.securityfocus.com/bid/74558
groups.google.com/forum/#%21searchin/docker-user/1.6.1/docker-user/47GZrihtr-4/nwgeOOFLexIJ