YaBB Bulletin Board 9.1.2000 allows remote attackers to read arbitrary files via a .. (dot dot) attack.
YabbSE 1.5.5c allows remote attackers to obtain sensitive information via a direct request to ssi_examples.php, which reveals the path.
YaBB SE 1.5.1 allows remote attackers to obtain sensitive information via a direct HTTP request to Admin.php, which reveals the full path in a PHP error message.