ubuntu-system-service 0.2.4 before 0.2.4.1. 0.2.3 before 0.2.3.1, and 0.2.2 before 0.2.2.1 does not properly use D-Bus for communication with a polkit authority, which allows local users to bypass intended access restrictions by leveraging a PolkitUnixProcess PolkitSubject race condition via a (1) setuid process or (2) pkexec process, a related issue to CVE-2013-4288.