Mandriva Linux Security Advisory 2013-230 – GNOME Display Manager before 2.21.1 allows local users to change permissions of arbitrary directories via a symlink attack on /tmp/.X11-unix/. The updated packages have been patched to correct this issue…. Mandriva Linux Security Advisory 2013-230 – GNOME Display Manager before 2.21.1 allows local users to change permissions of arbitrary directories via a symlink attack on /tmp/.X11-unix/. The updated packages have been patched to correct this issue.

Read more http://packetstormsecurity.com/files/123186/MDVSA-2013-230.txt