Heap-based buffer overflow in the Cirrus VGA implementation in (1) KVM before kvm-82 and (2) QEMU on Debian GNU/Linux and Ubuntu might allow local users to gain privileges by using the VNC console for a connection, aka the LGD-54XX "bitblt" heap overflow. NOTE: this issue exists because of an incorrect fix for CVE-2007-1320.
The protocol_client_msg function in vnc.c in the VNC server in (1) Qemu 0.9.1 and earlier and (2) KVM kvm-79 and earlier allows remote attackers to cause a denial of service (infinite loop) via a certain message.
Qemu 0.9.1 and earlier does not perform range checks for block device read or write requests, which allows guest host users with root privileges to access arbitrary memory and escape the virtual machine.