Use-after-free vulnerability in the virNetMessageFree function in rpc/virnetserverclient.c in libvirt 1.0.x before 1.0.2, 0.10.2 before 0.10.2.3, 0.9.11 before 0.9.11.9, and 0.9.6 before 0.9.6.4 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code by triggering certain errors during an RPC connection, which causes a message to be freed without being removed from the message queue.
The virNetServerProgramDispatchCall function in libvirt before 0.10.2 allows remote attackers to cause a denial of service (NULL pointer dereference and segmentation fault) via an RPC call with (1) an event as the RPC number or (2) an RPC number whose value is in a "gap" in the RPC dispatch table.
libvirt, possibly before 0.9.12, does not properly assign USB devices to virtual machines when multiple devices have the same vendor and product ID, which might cause the wrong device to be associated with a guest and might allow local users to access unintended USB devices.