gksu-polkit: root privilege escalation

From the Red Hat Bugzilla entry:

Miroslav Trmac reported that gksu-polkit ships with an extremely permissive PolicyKit policy configuration file. Because gksu-polkit allows a user to execute a program with administrative privileges, and because the default allow_active setting is "auth_self" rather than "auth_admin", any local user can use gksu-polkit to execute arbitrary programs (like a bash shell) with root privileges.