VDSM in Red Hat Enterprise Virtualization 3 and 3.2 allows privileged guest users to cause the host to become "unavailable to the managment server" via invalid XML characters in a guest agent response. NOTE: this issue is due to an incomplete fix for CVE-2013-0167.
https://bugzilla.redhat.com/show_bug.cgi?id=996166
http://rhn.redhat.com/errata/RHSA-2013-1155.html
http://gerrit.ovirt.org/gitweb?p=vdsm.git%3Ba=commit%3Bh=5fe1615b7949999fc9abd896bde63bf24f8431d6