The MITRE CVE dictionary describes this issue as:
The networkReloadIptablesRules function in 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.
Find out more about CVE-2011-4600 from the
MITRE CVE dictionary dictionary and
This issue affect Red Hat Enterprise Linux 6 and has been addressed via
https://rhn.redhat.com/errata/RHBA-2012-0013.html. Red Hat Enterprise Linux 5 is
not affected. The Red Hat Security Response Team has rated this issue as having
low security impact. For additional information, refer to the Issue Severity