ecryptfs-setup-swap in eCryptfs before 111 does not prevent the unencrypted swap partition from activating during boot when using GPT partitioning and certain versions of systemd, which allows local users to obtain sensitive information via unspecified vectors.
https://bugs.launchpad.net/ubuntu/+source/ecryptfs-utils/+bug/1447282
https://bazaar.launchpad.net/~ecryptfs/ecryptfs/trunk/revision/857
http://www.ubuntu.com/usn/USN-3032-1