The _prepopulate_request_walk function in the Prepopulate module 7.x-2.x before 7.x-2.1 for Drupal allows remote attackers to modify the (1) actions, (2) container, (3) token, (4) password, (5) password_confirm, (6) text_format, or (7) markup field type, and consequently have unspecified impact, via unspecified vectors.