Registration Form for WooCommerce <= 1.1.4 - Unauthenticated Privilege Escalation to 'user_roles' Parameter at Checkout
The Registration Form for WooCommerce plugin for WordPress is vulnerable to privilege escalation due to a missing allow-list check in the FormHandler::validate_checkout_fields() function in versions up to, and including, 1.1.4 The My Account registration path (validate_fields()) validates a submitted 'tgwcfb/user-roles' value against the form's configured allowed roles, but the checkout registration path (validate_checkout_fields(), hooked to woocommerce_after_checkout_validation) stores the raw $_POST['user_roles'] value in $this->valid_data without any allow-list enforcement, and add_user_data() then injects that value into woocommerce_new_customer_data as the new account's role. This makes it possible for unauthenticated attackers to elevate their privileges to Administrator by supplying a user_roles=administrator parameter when creating an account during checkout, resulting in full site takeover.