Re: Chances of guessing?

[mouse () Collatz McRCIM McGill EDU (der Mouse)]

> I've read the procedure for guessing sequence numbers and the like,
> and it seems simple enough, except on any system with a heavy load.
> For instance, take a machine that gets 20 new connections/second on
> average (fairly likely on a machine thats run as a WWW server for
> instance).  Given that most systems increment the sequence counter by
> some amount per new connection, and you can't predict how many new
> connections will occur in a given time interval it seems that this
> hole just got a lot harder to exploit.

A little harder.  If there is, say, an average of 1/10 second between
your initial probe and your attack packet, then all the attacker needs
to do is add in the per-connection value once or twice.  True,
depends on luck...but it doesn't make it hard enough that the program
won't succeed after a half-dozen tries.

                                        der Mouse

                            mouse () collatz mcrcim mcgill edu