source: https://www.securityfocus.com/bid/14078/info

Community Server Forums is prone to a cross-site scripting vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input.

An attacker may exploit these issues to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site, steal cookie-based authentication credentials, perform unauthorized actions, and disclose or modify sensitive information. Other attacks may also be possible. 

http://www.example.com/forum/search/SearchResults.aspx?q=><script>alert('CSS%20Vulnerable')</script><
b%20a=a%20&f=&u=