D-Bus 1.4.x through 1.6.x before 1.6.30, 1.8.x before 1.8.16, and 1.9.x before 1.9.10 does not validate the source of ActivationFailure signals, which allows local users to cause a denial of service (activation failure error returned) by leveraging a race condition involving sending an ActivationFailure signal before systemd responds.

D-Bus 1.3.0 through 1.6.x before 1.6.24 and 1.8.x before 1.8.8 does not properly close connections for processes that have terminated, which allows local users to cause a denial of service via a D-bus message containing a D-Bus connection file descriptor.

dbus 1.3.0 before 1.6.22 and 1.8.x before 1.8.6 allows local users to cause a denial of service (disconnect) via a certain sequence of crafted messages that cause the dbus-daemon to forward a message containing an invalid file descriptor.

libdbus 1.5.x and earlier, when used in setuid or other privileged programs in X.org and possibly other products, allows local users to gain privileges and execute arbitrary code via the DBUS_SYSTEM_BUS_ADDRESS environment variable. NOTE: libdbus maintainers state that this is a vulnerability in the applications that do not cleanse environment variables, not in libdbus itself: "we do not support use of libdbus in setuid binaries that do not sanitize their environment before their first call into libdbus."