The WP Ultimate CSV Importer plugin for WordPress is vulnerable to Remote Code Execution in versions up to, and including, 7.9.8 via the '->cus1' parameter. This allows authenticated attackers with author-level permissions or above, if the administrator previously grants access in the plugin settings, to execute code on the server. The author resolved this vulnerability by removing the ability for authors and editors to import files, please note that this means remote code execution is still possible for site administrators, use the plugin with caution.