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.
https://www.redhat.com/archives/fedora-package-announce/2008-February/msg00957.html
https://www.redhat.com/archives/fedora-package-announce/2008-February/msg00900.html
https://www.redhat.com/archives/fedora-package-announce/2008-February/msg00857.html
https://www.redhat.com/archives/fedora-package-announce/2008-February/msg00852.html
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9706
https://bugzilla.redhat.com/show_bug.cgi?id=433560
http://www.securityfocus.com/bid/28001
http://www.redhat.com/support/errata/RHSA-2008-0194.html
http://www.redhat.com/archives/fedora-package-announce/2008-February/msg00850.html
http://www.redhat.com/archives/fedora-package-announce/2008-February/msg00830.html
http://www.mandriva.com/security/advisories?name=MDVSA-2009:016
http://www.mandriva.com/security/advisories?name=MDVSA-2008:162
http://www.debian.org/security/2009/dsa-1799
http://secunia.com/advisories/35031
http://secunia.com/advisories/34642
http://secunia.com/advisories/29963
http://secunia.com/advisories/29172
http://secunia.com/advisories/29136
http://secunia.com/advisories/29129
http://secunia.com/advisories/29081
http://marc.info/?l=debian-security&m=120343592917055&w=2
http://lists.opensuse.org/opensuse-security-announce/2009-04/msg00003.html