A flaw was found in OpenStack Keystone. A remote attacker could exploit this vulnerability by sending a large HTTP request, specifically by providing a long tenant name when requesting a token. This could lead to a denial of service, consuming excessive CPU and memory resources on the affected system.
https://launchpad.net/keystone/grizzly/2013.1
https://github.com/openstack/keystone/commit/82c87e5638ebaf9f166a9b07a0155291276d6fdc
https://github.com/openstack/keystone/commit/7691276b869a86c2b75631d5bede9f61e030d9d8
https://bugzilla.redhat.com/show_bug.cgi?id=909012