YaBB Bulletin Board 9.1.2000 allows remote attackers to read arbitrary files via a .. (dot dot) attack.
https://exchange.xforce.ibmcloud.com/vulnerabilities/5254
https://euvd.enisa.europa.eu/vulnerability/EUVD-2000-0840
http://www.securityfocus.com/bid/1668
http://archives.neohapsis.com/archives/bugtraq/2000-09/0072.html