- Advisory ID: DRUPAL-SA-2005-007
- Project: Drupal core
- Date: 2005-11-30
- Security risk: less critical
- Impact: normal
- Where: from remote
- Vulnerability: XSS
Ahmed Saad has brought to our attention a creative way to enter malicious HTML content. Upon further investigation we found that interpretation of broken HTML/SGML and various quirks in interpretation of correctly formed, but non-sensical attribute values by various browsers also allows entering malicious HTML content. These can lead to XSS attacks.
Drupal 4.5.0, 4.5.1, 4.5.2, 4.5.3, 4.5.4, 4.5.5
Drupal 4.6.0, 4.6.1, 4.6.2, 4.6.3
- If you are running Drupal 4.5.x, then upgrade to Drupal 4.5.6.
- If you are running Drupal 4.6.x, then upgrade to Drupal 4.6.4.
We have developed a new XSS filtering system based on Ulf Harnhammar's kses library http://sourceforge.net/projects/kses/. This filtering only happens for Filtered HTML content so if you are trusting a user to access the Full HTML input format then said user can enter malicious content, so please revise your input format settings.
Filtered HTML now filters the style attribute unconditionally.
Filter writers can access this mechanism through the new filter_xss() function.
The security contact for Drupal can be reached at security at drupal.org or using the form at http://drupal.org/contact.
More information is available from http://drupal.org/security or from our security RSS feed http://drupal.org/security/rss.xml.