mount.cifs in cifs-utils 2.6 allows local users to determine the existence of arbitrary files or directories via the file path in the second argument, which reveals their existence in an error message.
https://bugzilla.samba.org/show_bug.cgi?id=8821
http://www.openwall.com/lists/oss-security/2012/03/27/6
http://www.openwall.com/lists/oss-security/2012/03/27/1
http://lists.opensuse.org/opensuse-security-announce/2012-04/msg00024.html