Re: Bypassing firewall

From: Cliff Rayman (cliffat_private)
Date: Tue Jan 25 2000 - 10:54:24 PST

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    yes. this is very possible and fairly trivial for any programmer
    who knows how to write networking code.
    
    cliff rayman
    genwax.com
    
    Mailing Lists wrote:
    
    > Hi!
    >
    > Back where I work, we are using a firewall the blocks everything coming in,
    > and gives internal users permission to use the www, ftp, pop and mail
    > ports.  (no icq, no aol, no nothing else).
    >
    > But I overheard one of my users bragging that it bypassed the firewall
    > using two linux machines doing port redirection.
    >
    > I did a little research on this and the most plausible way I found is that
    > he is running a linux inside the firewall which grabs everyhing on a
    > certain port (let's say the icq server port), then forward it through port
    > 80 to another linux box outside the firewall which make the actual call to
    > the icq server on the right port.  Is that possible?  Is there any other
    > alternatives he can be using?
    >
    > btw, I don't know what the firewall used is, I'm the sysadm for my
    > division, but we are using the corporate firewall.
    >
    > Thanks!
    



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