An issue was discovered in D-Bus before 1.12.24, 1.13.x and 1.14.x before 1.14.4, and 1.15.x before 1.15.2. An authenticated attacker can cause dbus-daemon and other programs that use libdbus to crash by sending a message with attached file descriptors in an unexpected format.

An issue was discovered in D-Bus before 1.12.24, 1.13.x and 1.14.x before 1.14.4, and 1.15.x before 1.15.2. An authenticated attacker can cause dbus-daemon and other programs that use libdbus to crash when receiving a message where an array length is inconsistent with the size of the element type.

An issue was discovered in D-Bus before 1.12.24, 1.13.x and 1.14.x before 1.14.4, and 1.15.x before 1.15.2. An authenticated attacker can cause dbus-daemon and other programs that use libdbus to crash when receiving a message with certain invalid type signatures.

dbus before 1.10.28, 1.12.x before 1.12.16, and 1.13.x before 1.13.12, as used in DBusServer in Canonical Upstart in Ubuntu 14.04 (and in some, less common, uses of dbus-daemon), allows cookie spoofing because of symlink mishandling in the reference implementation of DBUS_COOKIE_SHA1 in the libdbus library. (This only affects the DBUS_COOKIE_SHA1 authentication mechanism.) A malicious client with write access to its own home directory could manipulate a ~/.dbus-keyrings symlink to cause a DBusServer with a different uid to read and write in unintended locations. In the worst case, this could result in the DBusServer reusing a cookie that is known to the malicious client, and treating that cookie as evidence that a subsequent client connection came from an attacker-chosen uid, allowing authentication bypass.

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.