The WHMpress - WHMCS WordPress Integration Plugin plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 6.3-revision-0 via the whmpress_domain_search_ajax_extended_results() function. This makes it possible for unauthenticated attackers to include and execute arbitrary files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where images and other “safe” file types can be uploaded and included. This makes it possible for unauthenticated attackers to update arbitrary options on the WordPress site. Utilizing the /admin/services.php file, this can be leveraged to update the default role for registration to administrator and enable user registration for attackers to gain administrative user access to a vulnerable site.