source: https://www.securityfocus.com/bid/14984/info

EasyGuppy is prone to a directory traversal vulnerability.

The application fails to properly sanitize input supplied through HTTP POST requests or cookies.

Exploitation of this vulnerability could lead to a loss of confidentiality as arbitrary files are disclosed to an attacker. 

http://www.example.com/printfaq.php?lng=en&pg=/../../../../../../../etc/passwd%00