Cross-site scripting (XSS) vulnerability in the wp_explain_nonce function in the nonce AYS functionality (wp-includes/functions.php) for WordPress 2.0 before 2.0.9 and 2.1 before 2.1.1 allows remote attackers to inject arbitrary web script or HTML via the file parameter to wp-admin/templates.php, and possibly other vectors involving the action variable.