Improper query string handling in Django

The administrative interface in django.contrib.admin in Django before 1.1.3, 1.2.x before 1.2.4, and 1.3.x before 1.3 beta 1 does not properly restrict use of the query string to perform certain object filtering, which allows remote authenticated users to obtain sensitive information via a series of requests containing regular expressions, as demonstrated by a created_by__password__regex parameter.