The Bulk SEO Image plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to and including 1.1. This is due to missing or incorrect nonce validation on the plugin's settings page handler BulkSeoImage(), which dispatches to launchbulk() / BulkSeoImageGo() whenever the request contains $_POST['bulkseoimage']. No wp_nonce_field() is emitted in the form and no check_admin_referer()/wp_verify_nonce() is performed before bulk-overwriting the _wp_attachment_image_alt post meta for every image attached to every published post and/or page. This makes it possible for unauthenticated attackers to bulk-overwrite image ALT-text metadata across the site via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.