Solace Extra <= 1.5.3 - Missing Authorization to Unauthenticated Arbitrary Content Deletion via delete_previously_imported AJAX Action

The Solace Extra plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 1.5.3. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to permanently delete all content previously imported via the Starter Template feature, including posts, pages, media attachments, WooCommerce products, taxonomy terms, and sitebuilder templates. The required nonce is emitted on every wp-admin page via wp_localize_script() hooked to admin_enqueue_scripts without a page guard, meaning any Subscriber visiting /wp-admin/profile.php can obtain it; the handler is additionally registered via wp_ajax_nopriv_, making it reachable by fully unauthenticated users as well.