virtualenv.py in virtualenv before 1.5 allows local users to overwrite arbitrary files via a symlink attack on a certain file in /tmp/.
https://bitbucket.org/ianb/virtualenv/changeset/8be37c509fe5
http://secunia.com/advisories/47240
http://openwall.com/lists/oss-security/2011/12/19/5
http://openwall.com/lists/oss-security/2011/12/19/4
http://openwall.com/lists/oss-security/2011/12/19/2
http://lists.fedoraproject.org/pipermail/package-announce/2012-January/071643.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-January/071638.html