Re: Reactive Firewalls

[Rachel Rosencrantz <rachel.rosencrantz () predictive com>]

At 10:16 AM 2/12/98 -0600, Rick Smith wrote:
> At 9:38 AM +1100 2/12/98, Darren Reed wrote:
> > Personally, I'd prefer a service that fell victim to D.O.S attacks than
> > one which could be compromised.
>
> Outside of the intelligence agencies, I've found that Internet savvy
> enterprises generally consider denial of service to be as bad or worse a
> "compromise" as anything else a hacker might do. This is certainly becoming
> true in military environments.


Not to sound too much like a text book, but there are 3 critical aspects
in security.  Confidentiality, Integrity, and Availability.  

Some environments feel that one aspect is more critical than the others.
(Notably the TCB concept relies heavily on the confidentiality being
the greater good.)  Some places the integrity of the data is crical.
(I'd think the stock exchange might be one of those.)  In other
situations, availabilty is the most critical.  (Of course I'd think
that would also be the stock exchange.)  For an organization that
has determined that Availability is job one, a DOS attack
is going to be far worse than lost or change of data.  What would
a web design company do if no-one could get to their customer's
web sites?  

It depends on the business, the use of the network in critical functions,
and fundamentally Policy.  Of course, lots of companies out 
there don't really sit down and think about what is critical and
an asset before setting up these policies.  I'd certainly
think I'd want some Asset and risk assement done and a policy
put in place before I was made responsible for the firewall.  
Otherwise, how do you know which objective(s) (Confidentiality, integrity,
availabilty) is critical.  

Without that policy some VP can cause some troubles because
they couldn't get their (personal) stock quotes via the web because
you shut down the FW. 

-Rachel