Registration Form for WooCommerce <= 1.1.4 - Unauthenticated Privilege Escalation to 'user_roles' Parameter at Checkout

Summary

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.

Remediation

1. Inventory every themegrill Registration Form for WooCommerce deployment, including staging.
2. No fixed version appears in the public sources yet. Check the references below and the vendor directly.

References

• Referencehttps://www.wordfence.com/threat-intel/vulnerabilities/id/714d10b0-526c-4347-a369-85fc32ef3478?source=cve
• Referencehttps://plugins.trac.wordpress.org/browser/registration-form-for-woocommerce/tags/1.1.3/includes/FormHandler.php#L354
• Referencehttps://plugins.trac.wordpress.org/browser/registration-form-for-woocommerce/tags/1.1.3/includes/FormHandler.php#L407
• Referencehttps://plugins.trac.wordpress.org/changeset?old_path=%2Fregistration-form-for-woocommerce%2Ftags%2F1.1.4&new_path=%2Fregistration-form-for-woocommerce%2Ftags%2F1.1.5