Robuta

https://www.php.net/manual/en/refs.fileprocess.file.php
File System Related Extensions
php file systemrelated extensionsmanual
https://www.exploit-db.com/exploits/29278
Work System eCommerce 3.0.3/3.0.4 - 'forum.php' Remote File Inclusion.. webapps exploit for PHP platform
work systemecommerceforum