the next generation of nuke.c

[iceman () MBnet MB CA (Oliver Friedrichs)]

More of a denial of service attack, but with the current discussion on
bugtraq/firewalls regarding sequence number guessing, I thought I'd put
forward a method on killing an established TCP connection, besides the
(mis)usage of ICMP unreachable messages.  It would also appear, that
although this attack is more difficult to launch, it would also be more
difficult to prevent.

Since it's possible to guess sequence numbers of the packets in a TCP
connection, it seems it would be possible to then send a fake FIN message to
our target, followed directly by an ACK to acknowledge the closing
of the connection.

If you wanted to kill a connection, all you would have to do is flood one
of the ends with FIN/ACK packets until you get the sequence numbers
correct.

- Oliver