Fluent Forms Pro Add On Pack <= 6.1.17 - Missing Authorization to Unauthenticated Arbitrary Attachment Deletion

The Fluent Forms Pro Add On Pack plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 6.1.17. This is due to the `deleteFile()` method in the `Uploader` class lacking nonce verification and capability checks. The AJAX action is registered via `addPublicAjaxAction()` which creates both `wp_ajax_` and `wp_ajax_nopriv_` hooks. This makes it possible for unauthenticated attackers to delete arbitrary WordPress media attachments via the `attachment_id` parameter. Note: The researcher described file deletion via the `path` parameter using `sanitize_file_name()`, but the actual code uses `Protector::decrypt()` for path-based deletion which prevents exploitation. The vulnerability is exploitable via the `attachment_id` parameter instead.