Re: Firewall bypassing tool

[Jon <warchild () spoofed org>]

On Fri, Nov 01, 2002 at 12:28:40PM +0100, d_fence wrote:
> Hi all, 
> I read sometime ago about bypassing the firewall filters which block incoming 
> (initializing) SYN packets, by sending for example a SYN-FIN packet and 
> establishing that way a connection to a blocked port.. Now  I`m trying to  
> check wether my firewall would let through such packets, and so I`m searching 
> for a tool which would does this.. Do you know any such tools?

Nmap may do this, as will any worthy packet crafting utility.
  
Looks like the nemesis page is finally back up:
  
http://www.packetfactory.net/Projects/nemesis/                                                                          
     
  
While it was down, I needed a tool with precision control for crafting TCP
and UDP packets.  I wrote two -- tcp-tk and udp-tk.  They may do what you
need.  Then again, they may not.
  
http://spoofed.org/files/tcp-tk.c                                                                                       
     
http://spoofed.org/files/udp-tk.c                                                                                       
     

hth,

-jon