The Advanced Product Fields (Product Addons) for WooCommerce plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.6.17. This is due to missing or incorrect nonce validation on the 'maybe_duplicate' function. This makes it possible for unauthenticated attackers to duplicate and publish product field groups, including draft and pending field groups, via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.