dbus-glib -- privledge escalation

Sebastian Krahmer reports:

A privilege escalation flaw was found in the way dbus-glib, the
D-Bus add-on library to integrate the standard D-Bus library with
the GLib thread abstraction and main loop, performed filtering of
the message sender (message source subject), when the
NameOwnerChanged signal was received. A local attacker could use
this flaw to escalate their privileges.