Docker 1.3.2 allows remote attackers to execute arbitrary code with root privileges via a crafted (1) image or (2) build in a Dockerfile in an LZMA (.xz) archive, related to the chroot for archive extraction.
https://groups.google.com/forum/#%21msg/docker-user/nFAz-B-n4Bw/0wr3wvLsnUwJ
http://www.securityfocus.com/archive/1/534215/100/0/threaded