qemu-kvm before 0.11.0 disables VNC authentication when the password is cleared, which allows remote attackers to bypass authentication and establish VNC sessions.
rhn.redhat.com/errata/RHSA-2011-0345.html
secunia.com/advisories/42830
secunia.com/advisories/43272
secunia.com/advisories/43733
secunia.com/advisories/44393
ubuntu.com/usn/usn-1063-1
www.openwall.com/lists/oss-security/2011/01/10/3
www.openwall.com/lists/oss-security/2011/01/11/1
www.openwall.com/lists/oss-security/2011/01/12/2
www.osvdb.org/70992
bugs.launchpad.net/ubuntu/+source/libvirt/+bug/697197
exchange.xforce.ibmcloud.com/vulnerabilities/65215