Re: [9fans] SSH Version2

["Russ Cox" <rsc@plan9.bell-labs.com>]

> ever heard of ettercap? the ultimate in script kiddie packet sniffing
> technology? it can break ssh1.
> http://ettercap.sourceforge.net/

that's not true.  it can stand in as a man-in-the-middle
for an active attack on ssh1.  that's only going to work
if you've never connected to the host before, or if you
ignore the man-in-the-middle warnings when the other end's
host key doesn't work out right.  to do that requires you
are proxy arping for the victim server, which limits the
attack even further.

from their readme:

5.4.4 SSH1 MAN-IN-THE-MIDDLE

 When the connection starts (remember that we are the master-of-packets, all
 packets go through ettercap) we substitute the server public key with one
 generated on the fly and save it in a list so we can remember that this
 server has been poisoned before.
 Then the client send the packet containing the session key ciphered with
 our key, so we are able to decipher it and sniff the real 3DES session key.
 Now we encrypt the packet with the correct server public key and forward it
 to the SSH daemon.
 The connection is established normally, but we have the session key !!
 Now we can decrypt all the traffic and sit down watching the stream !
 The connection will remain active even if we exit from ettercap, because
 ettercap doesn't proxy it (like dsniff). After the exchange of the keys,
 ettercap is only a spectator... ;)

russ