The Contact Form by Bit Form: Multi Step Form, Calculation Contact Form, Payment Contact Form & Custom Contact Form builder plugin for WordPress is vulnerable to generic SQL Injection via the id parameter in versions 2.0 to 2.13.9 due to insufficient escaping on the user-supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with Administrator-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.
https://plugins.trac.wordpress.org/browser/bit-form/tags/2.13.6/includes/Admin/AdminAjax.php#L1108