source: https://www.securityfocus.com/bid/52471/info

Max's Guestbook is prone to multiple remote vulnerabilities.

Exploiting these issues could allow an attacker to execute arbitrary HTML and script code in the context of the affected browser, steal cookie-based authentication credentials, and execute arbitrary local scripts in the context of the webserver process. Other attacks are also possible.

Max's Guestbook 1.0 is vulnerable; other versions may also be affected.

http://www.example.com/max/index.php?page=../../../../../../../../../../../../../../../../../etc/passwd%00