source: https://www.securityfocus.com/bid/27075/info

Kontakt Formular is prone to a remote file-include vulnerability because it fails to sufficiently sanitize user-supplied data.

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

This issue affects Kontakt Formular 1.4; other versions may be vulnerable as well.

http://www.example.com/[path]/includes/function.php?root_path=[Shellcode]