Debian Linux Security Advisory 3161-1 – Simon McVittie discovered a local denial of service flaw in dbus, an asynchronous inter-process communication system. On systems with systemd-style service activation, dbus-daemon does not prevent forged ActivationFailure messages from non-root processes. A malicious local user could use this flaw to trick dbus-daemon into thinking that systemd failed to activate a system service, resulting in an error reply back to the requester.