In a prior post, I described how to use telnet to verify that the HTTP TRACE command is disabled. A commenter asked:

What if telnet is actively being blocked… is there another way to invoke the TRACE request in an attempt to verify whether the potential vulnerability exists?

My immediate reaction was that I needed to research how to do this. What a fool I am…

The fact of the matter is that if an HTTP connection is able to connect to the server than the method I described will still work. Because we are using telnet to impersonate a browser – connecting via port 80 – even if telnet is blocked (usually port 23), using telnet via port 80 will still work. If the browser can connect via this way, so can telnet via port 80.