Re:Bypassing firewall

[TDyson () sybex com]

If the firewall is just a packet filter, rather than proxy based, even
netcat could do the job I bet.

Time to check out your company's acceptable use policy to see if it forbids
this sort of thing.  If it does, contact HR and pursue disciplinary action.
If it doesn't, ask the user how he did it, so you can increase your own
skill set.


Thom Dyson
Director of Information Services
Sybex, Inc

> 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?