Re: [fw-wiz] Firewall best practices


I agree that it would generate a warning but the issue you then have
is users go "Huh?, what?" and click on allow anyway.

To quote a presenter at a security course I attended "If the user is
given the choice between security and seeing a dancing snowman, the
snowman wins every time!".

The "advantage" that SSL had for the general populous for nonEvil(tm)
purposes was that we could say that if the little padlock was there
when they went to their internet banking site that their data was
safe*. These new technologies, although neccessary for a host of other
reasons such ad data leakage, covert communications etc etc etc
unfortunately push the responsibility for the security of personal
data closer to the people that it important to. Unfortunately they are
the least able to deal with it in general and as much as we TRY to
teach them ( and I do really try). We do try to protect users from
themselves, but there is only so much we can do.

I am not saying that the MITM function is not without its merrit (in
whatever form you see as the best for security) but it does then pose
other interesting positions to consider.

Just my $AU0.02 worth!


* Yes I know "safe" is a relative term in this context, but youget the idea! :-)

On 28 April 2010 18:13, Cian Brennan <cian.brennan@xxxxxxxxxxxxxxx> wrote:
On Tue, Apr 27, 2010 at 11:12:40AM -0500, Fetch, Brandon wrote:
Too late:

And these devices are already in, imagine one of these with a wildcard certificate running at a coffee house, or at the aggregation point within a provider's CO POP...

Where it would generate cert errors for every user?

These only make sense where you can install the proxy's wildcard cert on all of
the client machines. Neither coffee houes, nor ISPs can do this.

-----Original Message-----
From: firewall-wizards-bounces@xxxxxxxxxxxxxxxxxxxxx [mailto:firewall-wizards-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of John Morrison
Sent: Tuesday, April 27, 2010 5:45 AM
To: Firewall Wizards Security Mailing List
Cc: mjr@xxxxxxxxx; Firewall Wizards Security Mailing List
Subject: Re: [fw-wiz] Firewall best practices

My understanding of https (and other PKI-based encryption) is that
only the holder of the private key can decrypt the data encrypted with
the other (public) key in the pair. My view is that the firewall can
only decrypt and inspect https traffic if it is acting as the server
to the external client. It can't intercept and decrypt https traffic
destined for another device - the real server. If it did https would
be worthless. Any hacker could buy such a firewall to sniff and
decrypt all https traffic.

On 23 April 2010 20:18,  <david@xxxxxxx> wrote:
On Fri, 23 Apr 2010, Martin Barry wrote:

$quoted_author = "Marcus J. Ranum" ;

That's why firewalls need to go back to doing what they
originally did, and parsing/analyzying the traffic that
flows through them, rather than "stateful packet
inspection" (which, as far as I can tell, means that
there's a state-table entry saying "I saw SYN!")

Marcus, are you referring to DPI or proxies or both or something else

If the firewall doesn't understand the data it's passing,
it's not a firewall, it's a hub.

If an application emulates HTTPS traffic and is proxy aware, how do you
the difference?

There are firewalls on the market that can decrypt HTTPS traffic (and I
believe be configured to block any traffic that they can't decrypt)

David Lang
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