The User module in Drupal 7.x before 7.44 allows remote authenticated users to gain privileges via vectors involving contributed or custom code that triggers a rebuild of the user profile form.
https://www.drupal.org/SA-CORE-2016-002
http://www.securityfocus.com/bid/91230
http://www.openwall.com/lists/oss-security/2016/07/13/7