The virConnectDomainXMLToNative API function in libvirt 1.1.0 through 1.1.3 checks for the connect:read permission instead of the connect:write permission, which allows attackers to gain domain:write privileges and execute Qemu binaries via crafted XML. NOTE: some of these details are obtained from third party information.
https://bugzilla.redhat.com/show_bug.cgi?id=1015259
http://www.ubuntu.com/usn/USN-2026-1
http://www.securitytracker.com/id/1029241
http://wiki.libvirt.org/page/Maintenance_Releases
http://security.gentoo.org/glsa/glsa-201412-04.xml
http://secunia.com/advisories/60895
http://secunia.com/advisories/55210
http://libvirt.org/git/?p=libvirt.git%3Ba=commit%3Bh=57687fd6bf7f6e1b3662c52f3f26c06ab19dc96c