retrieve_password.pl in DCForum 6.x and 2000 generates predictable new passwords based on a sessionID, which allows remote attackers to request a new password on behalf of another user and use the sessionID to calculate the new password for that user.
dcboard.cgi in DCForum 2000 1.0 allows remote attackers to execute arbitrary commands by uploading a Perl program to the server and using a .. (dot dot) in the AZ parameter to reference the program.
upload_file.pl in DCForum 2000 1.0 allows remote attackers to upload arbitrary files without authentication by setting the az parameter to upload_file.