source: https://www.securityfocus.com/bid/38234/info

CMS Made Simple is prone to a local file-include vulnerability and a cross-site scripting vulnerability because it fails to properly sanitize user-supplied input.

An attacker can exploit the local file-include vulnerability using directory-traversal strings to view and execute local files within the context of the webserver process. Information harvested may aid in further attacks.

The attacker may leverage the cross-site scripting issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may let the attacker steal cookie-based authentication credentials and launch other attacks.

CMS Made Simple 1.6.6 is affected; other versions may also be vulnerable. 

http://www.example.com/cmsmadesimple/index.php?page=tags-in-the-core&showtemplate=false"><script>alert('XSS')</script>
http://www.example.com/cmsmadesimple/index.php?mact=News%2ccntnt01%2c%5c..%5c..%5c%5c..%5c..%5c%5c..%5c..%5c%5c..%5c..%5c%5c..%5c..%5c%5cboot.ini%00%2c0&cntnt01articleid=1&cntnt01showtemplate=false&cntnt01returnid=39