Red Hat libvirt 0.2.0 through 0.8.2 creates iptables rules with improper mappings of privileged source ports, which allows guest OS users to bypass intended access restrictions by leveraging IP address and source-port values, as demonstrated by copying and deleting an NFS directory tree.
libvirt.org/news.html
lists.fedoraproject.org/pipermail/package-announce/2010-July/044520.html
lists.fedoraproject.org/pipermail/package-announce/2010-July/044579.html
lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html
ubuntu.com/usn/usn-1008-1
ubuntu.com/usn/usn-1008-2
ubuntu.com/usn/usn-1008-3
www.redhat.com/support/errata/RHSA-2010-0615.html
www.vupen.com/english/advisories/2010/2062
www.vupen.com/english/advisories/2010/2763
bugs.launchpad.net/ubuntu/+source/libvirt/+bug/591943
bugzilla.redhat.com/show_bug.cgi?id=602455