The "create an instance" API in OpenStack Compute (Nova) Folsom, Grizzly, and Havana does not properly enforce the os-flavor-access:is_public property, which allows remote authenticated users to boot arbitrary flavors by guessing the flavor id. NOTE: this issue is due to an incomplete fix for CVE-2013-2256.
https://bugs.launchpad.net/ossa/+bug/1212179
http://rhn.redhat.com/errata/RHSA-2013-1199.html
http://lists.openstack.org/pipermail/openstack-announce/2013-August/000138.html