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Re: Microsoft Windows and *nix Telnet Port Number Argument Obfuscation


From: Nick FitzGerald <nick () virus-l demon co uk>
Date: Fri, 10 Jun 2005 03:02:01 +1200

Kristian Hermansen wrote:

This has been known since Adam was a cowboy.

Although I don't believe that your claim is unlikely, it would have been
nice to post a link to the original discovery to back it up.  ...

It was never "originally discovered".  All manner of commandline 
parsing of text to numbers has been doing this in many places for quite 
some time.  I did not post a URL to back it up as I have no idea where 
I first came across this and it was so long ago that the odds of that 
source still being available to cite are probably pretty low and I have 
better things to do with my time.

...  Everyone
that I have showed this to, personally, has not seen it before.  ...

Maybe that says that something about the "everyones" you know, rather 
than saying anything about this minor factoid?

...  And,
after some google searching, I could not locate anyone else either that
talked about this -- the closest thing was an old Microsoft telnet
advisory that didn't mention this behavior specifically.

I just did a few minutes Googling onlikely phrases and turned up 
hundreds of hits.  Haven't got time to wade through them to find which 
are most relevant, but it seems many people have come across similar 
issues in commandline parsing code "wrapping" when they parse strings 
representing values larger than 65535 that are supposed to be unsigned 
16-bit integers and many of those are in the context of specifying port 
numbers for TCP/IP networking.

With that said, I would like to ask anyone who has info about the
original discovery to please post it here (Nick didn't respond to my
email).  ...

Sorry -- been busy but I intended to (I'll write separately and explain 
those idiomatic and possibly anachronistic expressions you couldn't 
parse...).

...  I am interested to know more about it, and maybe the original
discoverer found other things as well...thanks

This stuff goes back to the ark -- I doubt those guys give a toss about 
this list and what is discussed here...


Regards,

Nick FitzGerald

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