A certain Red Hat script for sudo 1.7.2 on Red Hat Enterprise Linux (RHEL) 5 allows local users to overwrite arbitrary files via a symlink attack on the /var/tmp/nsswitch.conf.bak temporary file.
http://www.securityfocus.com/bid/54868
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html