The encrypted private-directory setup process in utils/ecryptfs-setup-private in ecryptfs-utils before 90 does not properly ensure that the passphrase file is created, which might allow local users to bypass intended access restrictions at a certain time in the new-user creation steps.
https://launchpad.net/ecryptfs/+download
https://bugzilla.redhat.com/show_bug.cgi?id=729465
http://www.ubuntu.com/usn/USN-1188-1
http://lists.opensuse.org/opensuse-security-announce/2011-08/msg00009.html