source: http://www.securityfocus.com/bid/5211/info

Lil' HTTP server is a web server application for Windows environments and is maintained by Summit Computer Networks.

It is possible for attackers to construct a URL to the 'pbcgi.cgi' script which includes scripting code to execute in a user's browser. As a result, when an innocent user follows such a link, the script code will execute within the context of the hosted site. 

http://localhost:81/pbcgi.cgi?name=Matthew%20Murphy&email=%3CSCRIPT%3Ealert%28%27xss%27%29%3B%3C%2FSCRIPT%3E