The default configuration in mate-settings-daemon 1.5.3 allows local users to change the timezone for the system via a crafted D-Bus call.
https://bugzilla.redhat.com/show_bug.cgi?id=878102
http://lists.fedoraproject.org/pipermail/package-announce/2013-March/099552.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-March/099545.html