Race condition in daemon/slave.c in gdm before 2.14.1 allows local users to gain privileges via a symlink attack when gdm performs chown and chgrp operations on the .ICEauthority file.
gnome screensaver before 2.14, when running on an X server with AllowDeactivateGrabs and AllowClosedownGrabs enabled, allows attackers with physical access to cause the screensaver to crash and access the session via the Ctl+Alt+Keypad-Multiply keyboard sequence, which removes the grab from gnome.