WooCommerce Product Attachment <= 2.1.8 - Cross-Site Request Forgery

The WooCommerce Product Attachment plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.1.8. This is due to missing nonce validation on the wcpoa_order_checkout_attachment_save() function. This makes it possible for unauthenticated attackers to save checkout page attachments on the behalf of other users via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.