welcome.py in xdiagnose before 2.5.2ubuntu0.1 allows local users to overwrite arbitrary files via a symlink attack on a temporary file with a predictable name in /tmp.
https://exchange.xforce.ibmcloud.com/vulnerabilities/79475
https://bugs.launchpad.net/ubuntu/+source/xdiagnose/+bug/1036211
http://www.ubuntu.com/usn/USN-1591-1