Cross-site scripting (XSS) vulnerability in the LoginToboggan module 4.7.x-1.0, 4.7.x-1.x-dev, and 5.x-1.x-dev before 20070712 for Drupal, when configured to display a "Log out" link, allows remote attackers to inject arbitrary web script or HTML via a crafted username.  NOTE: Drupal sanitizes the username by removing certain characters, so this might not be a vulnerability on default installations.