CVE 2010-2242
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.
See the 
CVE page on Mitre.org
for more details.
