source: https://www.securityfocus.com/bid/9517/info

Web Blog is prone to a file disclosure vulnerability. Remote attackers may gain access to files on the system hosting the server that reside outside of the server root by submitting a malicious request that contains directory traversal sequences. This would permit the attacker to access files that are readable by the server and could disclose sensitive information.

http://www.example.com/directory/blog.cgi?submit=ViewFile&month=[month]&year=[year]&file=/../../../../../../../../../../../../../../../../etc/passwd