What the vulnerability does
01Description
The WPFunnels plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 3.12.13. This is due to the plugin registering the 'wpfnl_load_payment' AJAX action for both authenticated and unauthenticated (wp_ajax_nopriv_) users and the underlying add_offer_product_to_cart() function performing no nonce verification, no capability check, and no validation that the attacker-supplied product_id is the offer product actually configured on the attacker-supplied step_id. This makes it possible for unauthenticated attackers to add arbitrary WooCommerce products to a cart at any discounted price configured on any funnel step, enabling price manipulation and revenue loss at checkout.
