libvirt is vulnerable to authorization bypass attacks. The vulnerability exists as the networkReloadIptablesRules
function of network/bridge_driver.c
in libvirt before 0.9.9 does not properly handle firewall rules on bridge networks when libvirtd is restarted, which might allow remote attackers to bypass intended access restrictions via a (1) DNS or (2) DHCP query.
libvirt.org/git/?p=libvirt.git%3Ba=commitdiff%3Bh=ae1232b298323dd7bef909426e2ebafa6bca9157
libvirt.org/news-2012.html
www.ubuntu.com/usn/USN-2867-1
access.redhat.com/kb/docs/DOC-67874
access.redhat.com/security/cve/CVE-2011-4600
bugzilla.redhat.com/show_bug.cgi?id=759061
bugzilla.redhat.com/show_bug.cgi?id=760442
bugzilla.redhat.com/show_bug.cgi?id=769674
bugzilla.redhat.com/show_bug.cgi?id=770957
bugzilla.redhat.com/show_bug.cgi?id=770959
docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.2_Technical_Notes/libvirt.html#RHBA-2012-0013
rhn.redhat.com/errata/RHBA-2012-0013.html
rhn.redhat.com/errata/RHSA-2011-1849.html
www.redhat.com/security/data/cve/CVE-2011-4127.html