The title of book pages is not always properly escaped, enabling users with the “create book content” permission or the permission to edit any node in the book hierarchy to insert arbitrary HTML and script code into pages. Such a Cross Site Scripting attack may lead to the attacker gaining administrator access.
https://drupal.org/node/324824
This vulnerability affects the following application versions:
- Drupal 6.0
- Drupal 6.1
- Drupal 6.2
- Drupal 6.3
- Drupal 6.4
- Drupal 6.5