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.
http://lists.opensuse.org/opensuse-security-announce/2009-01/msg00004.html
http://lists.opensuse.org/opensuse-security-announce/2009-04/msg00003.html
http://secunia.com/advisories/33293
http://secunia.com/advisories/33303
http://secunia.com/advisories/33350
http://secunia.com/advisories/33568
http://secunia.com/advisories/34642
http://secunia.com/advisories/35062
http://securityreason.com/securityalert/4803
http://securitytracker.com/id?1021488
http://securitytracker.com/id?1021489
https://exchange.xforce.ibmcloud.com/vulnerabilities/47561
https://www.redhat.com/archives/fedora-package-announce/2008-December/msg01223.html
http://www.coresecurity.com/content/vnc-remote-dos
http://www.ubuntu.com/usn/usn-776-1