OpenStack Keystone Essex (2012.1) and Folsom (2012.2) does not properly handle EC2 tokens when the user role has been removed from a tenant, which allows remote authenticated users to bypass intended authorization restrictions by leveraging a token for the removed user role.
https://github.com/openstack/keystone/commit/9d68b40cb9ea818c48152e6c712ff41586ad9653
https://github.com/openstack/keystone/commit/8735009dc5b895db265a1cd573f39f4acfca2a19
https://github.com/openstack/keystone/commit/37308dd4f3e33f7bd0f71d83fd51734d1870713b
https://exchange.xforce.ibmcloud.com/vulnerabilities/80333
https://bugs.launchpad.net/keystone/+bug/1064914
http://www.ubuntu.com/usn/USN-1641-1
http://www.securityfocus.com/bid/56726
http://www.openwall.com/lists/oss-security/2012/11/28/6
http://www.openwall.com/lists/oss-security/2012/11/28/5
http://secunia.com/advisories/51436
http://secunia.com/advisories/51423
http://rhn.redhat.com/errata/RHSA-2012-1557.html
http://rhn.redhat.com/errata/RHSA-2012-1556.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-December/094286.html