dbus-daemon in D-Bus before 1.0.3, and 1.1.x before 1.1.20, recognizes send_interface attributes in allow directives in the security policy only for fully qualified method calls, which allows local users to bypass intended access restrictions via a method call with a NULL interface.
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.