Heads up! This is a really nasty one.
OpenStack Security Advisory: 2012-013
Date: August 30, 2012
Title: Lack of authorization for adding users to tenants
Reporter: Dolph Mathews (Rackspace)
Affects: Essex, Folsom
Dolph Mathews reported a vulnerability in Keystone. When attempting to
update a user’s default tenant, Keystone will only partially deny the
request when a user is not authorized to complete this action. The API
responds with 401 Not Authorized and the user’s default tenant is not
changed. However, the user is still granted membership to this new
tenant.The result is that any client that can reach the administrative
API (deployed on port 35357, by default) can add any user to any tenant.
This fix will be included in the folsom-rc1 development milestone and in
a future Essex (2012.1) release.