source: https://www.securityfocus.com/bid/5572/info

OmniHTTPD is a webserver for Microsoft Windows operating systems. OmniHTTPD supports a number of CGI extensions which provide dynamic content.

A HTML injection vulnerability has been reported in the '/cgi-bin/redir.exe' sample CGI included with OmniHTTPD. Reportedly, it is possible for an attacker to URL encode the newline character (%0D) and insert malicious HTML code. A vulnerable server receiving a malformed request will return a 302 redirect HTTP response containing the malicious attacker-supplied code.

http://localhost/cgi-bin/redir.exe?URL=http%3A%2F%2Fwww%2Eyahoo%2Ecom%2F%0D%
0A%0D%0A%3CSCRIPT%3Ealert%28document%2EURL%29%3C%2FSCRIPT%3E