source: https://www.securityfocus.com/bid/7319/info

Super Guestbook has been reported prone to a sensitive information disclosure weakness.

An attacker may disclose sensitive information regarding the Super Guestbook install by sending a HTTP request for a Guest Book configuration file. Details including administration credentials are displayed in the attackers browser. 

http://www.example.com/cgi-bin/SGB_DIR/superguestconfig