OpenStack Swift before 1.9.1 in Folsom, Grizzly, and Havana allows authenticated users to cause a denial of service ("superfluous" tombstone consumption and Swift cluster slowdown) via a DELETE request with a timestamp that is older than expected.
https://review.openstack.org/#/c/40646/
https://review.openstack.org/#/c/40645/
https://review.openstack.org/#/c/40643/
https://bugs.launchpad.net/swift/+bug/1196932
http://www.ubuntu.com/usn/USN-2001-1
http://www.openwall.com/lists/oss-security/2013/08/07/6