PHP remote file inclusion vulnerability in admin/addentry.php in phpBB Advanced Guestbook 2.4.0 and earlier, when register_globals is enabled, allows remote attackers to include arbitrary files via the phpbb_root_path parameter.
https://www.exploit-db.com/exploits/1725
https://www.exploit-db.com/exploits/1723
https://exchange.xforce.ibmcloud.com/vulnerabilities/26217
http://www.vupen.com/english/advisories/2006/1600