qemu -- buffer overflow vulnerability in VNC

Prasad J Pandit, Red Hat Product Security Team, reports:

Qemu emulator built with the VNC display driver support is
vulnerable to a buffer overflow flaw leading to a heap memory
corruption issue. It could occur while refreshing the server
display surface via routine vnc_refresh_server_surface().
A privileged guest user could use this flaw to corrupt the heap
memory and crash the Qemu process instance OR potentially use it
to execute arbitrary code on the host.