WordPress and WordPress MU before 2.8.1 exhibit different behavior for a failed login attempt depending on whether the user account exists, which allows remote attackers to enumerate valid usernames. NOTE: the vendor reportedly disputes the significance of this issue, indicating that the behavior exists for "user convenience."

The forgotten mail interface in WordPress and WordPress MU before 2.8.1 exhibits different behavior for a password request depending on whether the user account exists, which allows remote attackers to enumerate valid usernames. NOTE: the vendor reportedly disputes the significance of this issue, indicating that the behavior exists for "user convenience."

Cross-site scripting (XSS) vulnerability in the choose_primary_blog function in wp-includes/wpmu-functions.php in WordPress MU (WPMU) before 2.7 allows remote attackers to inject arbitrary web script or HTML via the HTTP Host header.

wp-admin/options.php in WordPress MU before 1.3.2, and WordPress 2.3.2 and earlier, does not properly validate requests to update an option, which allows remote authenticated users with manage_options and upload_files capabilities to execute arbitrary code by uploading a PHP script and adding this script's pathname to active_plugins.

Cross-site scripting (XSS) vulnerability in wp-admin/wp-blogs.php in Wordpress MU (WPMU) before 2.6 allows remote attackers to inject arbitrary web script or HTML via the (1) s and (2) ip_address parameters.

Cross-site scripting (XSS) vulnerability in wp-newblog.php in WordPress multi-user (MU) 1.0 and earlier allows remote attackers to inject arbitrary web script or HTML via the weblog_id parameter (Username field).

Unrestricted file upload vulnerability in WordPress before 2.2.1 and WordPress MU before 1.2.3 allows remote authenticated users to upload and execute arbitrary PHP code by making a post that specifies a .php filename in the _wp_attached_file metadata field; and then sending this file's content, along with its post_ID value, to (1) wp-app.php or (2) app.php.

Unrestricted file upload vulnerability in (1) wp-app.php and (2) app.php in WordPress 2.2.1 and WordPress MU 1.2.3 allows remote authenticated users to upload and execute arbitrary PHP code via unspecified vectors, possibly related to the wp_postmeta table and the use of custom fields in normal (non-attachment) posts. NOTE: this issue reportedly exists because of an incomplete fix for CVE-2007-3543.