The OpenID module in Drupal 6.x before 6.18, and the OpenID module 5.x before 5.x-1.4 for Drupal, violates the OpenID 2.0 protocol by not checking for reuse of openid.response_nonce values, which allows remote attackers to bypass authentication by leveraging an assertion from an OpenID provider.

The OpenID module in Drupal 6.x before 6.18, and the OpenID module 5.x before 5.x-1.4 for Drupal, violates the OpenID 2.0 protocol by not verifying the openid.return_to value, which allows remote attackers to bypass authentication by leveraging an assertion from an OpenID provider.

The OpenID module in Drupal 6.x before 6.18, and the OpenID module 5.x before 5.x-1.4 for Drupal, violates the OpenID 2.0 protocol by not ensuring that fields are signed, which allows remote attackers to bypass authentication by leveraging an assertion from an OpenID provider.

The comment module in Drupal 5.x before 5.23 and 6.x before 6.18 allows remote authenticated users with certain privileges to bypass intended access restrictions and reinstate removed comments via a crafted URL, related to an "unpublishing bypass" issue.

Multiple cross-site scripting (XSS) vulnerabilities in Drupal 6.x before 6.18 allow remote authenticated users with certain privileges to inject arbitrary web script or HTML via (1) an action description, (2) an action message, (3) a node, or (4) a taxonomy term, related to the actions feature and the trigger module.

The upload module in Drupal 5.x before 5.23 and 6.x before 6.18 does not properly support case-insensitive filename handling in a database configuration, which allows remote authenticated users to bypass the intended restrictions on downloading a file by uploading a different file with a similar name.

Cross-site scripting (XSS) vulnerability in the Menu module (modules/menu/menu.admin.inc) in Drupal Core 6.x before 6.15 allows remote authenticated users with permissions to create new menus to inject arbitrary web script or HTML via a menu description, which is not properly handled in the menu administration overview.

Cross-site scripting (XSS) vulnerability in the Contact module (modules/contact/contact.admin.inc or modules/contact/contact.module) in Drupal Core 5.x before 5.21 and 6.x before 6.15 allows remote authenticated users with "administer site-wide contact form" permissions to inject arbitrary web script or HTML via the contact category name.

Cross-site scripting (XSS) vulnerability in the Forum module in Drupal 6.x before 6.13 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Multiple cross-site scripting (XSS) vulnerabilities in Drupal 5.x before 5.18 and 6.x before 6.12 allow (1) remote authenticated users to inject arbitrary web script or HTML via crafted UTF-8 byte sequences that are treated as UTF-7 by Internet Explorer 6 and 7, which are not properly handled in the "HTML exports of books" feature; and (2) allow remote authenticated users with administer taxonomy permissions to inject arbitrary web script or HTML via the help text of an arbitrary vocabulary. NOTE: vector 1 exists because of an incomplete fix for CVE-2009-1575.