The dbus-daemon in D-Bus 1.2.x through 1.4.x, 1.6.x before 1.6.20, and 1.8.x before 1.8.4, sends an AccessDenied error to the service instead of a client when the client is prohibited from accessing the service, which allows local users to cause a denial of service (initialization failure and exit) or possibly conduct a side-channel attack via a D-Bus message to an inactive service.

A denial of service flaw was found in the way UNIX system D-BUS format string wrapper implementation of D-BUS, a system for sending messages between applications, used to measure the length of the provided format string and its arguments in certain circumstances. A remote attacker could supply a specially-crafted input to an application / service, utilizing the services / functionality of the libdbus library that, when processed would lead to that application / service crash.

References: [1] http://www.openwall.com/lists/oss-security/2013/06/13/2

Relevant upstream patch: [2] http://cgit.freedesktop.org/dbus/dbus/commit/?id=954d75b2b64e4799f360d2a6bf9cff6d9fee37e7

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.

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.