Drupal versions 4.6.0 through 4.6.3 suffer from an authentication bypass flaw when using PHP5.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/42032/DRUPAL-SA-2005-009.txt
Source: https://packetstormsecurity.com/files/42032/DRUPAL-SA-2005-009.txt.html