RE: Bypassing firewall

From: Riley, Steven (steven.rileyat_private)
Date: Tue Jan 25 2000 - 07:43:34 PST

  • Next message: Mark Holloway: "Re: Linux firewall options"

    Phrack 56-16 had a good article on what you suggested. I think the article
    was called 'Piercing a Firewall'.
     
    
    -----Original Message-----
    From: Mailing Lists [mailto:mlistat_private]
    Sent: 23 January 2000 16:06
    To: firewall-wizardsat_private
    Subject: Bypassing firewall
    
    
    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! 
    
     
    ===================================================
    This communication contains information which is confidential and 
    may also be privileged.  It is for the exclusive use of the 
    intended recipient(s).  If you are not the intended recipient(s), 
    please note that any distribution, copying or use of this 
    communication or the information in it is strictly prohibited.  
    If you have received this communication in error, please notify 
    the sender immediately and then destroy any copies of it.
    --
    MCI WorldCom Year 2000 information http://www.wcom.co.uk/2000
    



    This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 13:59:01 PDT