Openstack Compute (Nova) Folsom, 2012.1, and 2011.3 does not limit the number of security group rules, which allows remote authenticated users with certain permissions to cause a denial of service (CPU and hard drive consumption) via a network request that triggers a large number of iptables rules.
https://lists.launchpad.net/openstack/msg10268.html
https://github.com/openstack/nova/commit/a67db4586f70ed881d65e80035b2a25be195ce64
https://github.com/openstack/nova/commit/8c8735a73afb16d5856f0aa6088e9ae406c52beb
https://github.com/openstack/nova/commit/1f644d210557b1254f7c7b39424b09a45329ade7
https://exchange.xforce.ibmcloud.com/vulnerabilities/75243
https://bugs.launchpad.net/nova/+bug/969545
http://ubuntu.com/usn/usn-1438-1
http://secunia.com/advisories/49048
http://secunia.com/advisories/49034
http://lists.fedoraproject.org/pipermail/package-announce/2012-May/079551.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-May/079434.html