Multiple PHP remote file inclusion vulnerabilities in VistaBB 2.0.33 and earlier allow remote attackers to execute arbitrary PHP code via a URL in the phpbb_root_path parameter in (1) includes/functions_mod_user.php or (2) includes/functions_portal.php.
https://www.exploit-db.com/exploits/2251
http://www.vupen.com/english/advisories/2006/3369