The Cost Calculator Builder plugin for WordPress is vulnerable to Unauthenticated Price Manipulation and Insecure Direct Object Reference (IDOR) in all versions up to, and including, 4.0.1 only when used in combination with Cost Calculator Builder PRO. This is due to the ccb_woocommerce_payment AJAX action being registered via wp_ajax_nopriv, making it accessible to unauthenticated users, and the renderWooCommercePayment() function passing user-controlled data directly to CCBWooCheckout::init() without authorization checks. This makes it possible for unauthenticated attackers to add WooCommerce products to their cart with attacker-controlled prices.