IDS mailing list archives

RE: Firewalls (was Re: IDS evaluations procedures)


From: "Swift, David" <dswift () ipolicynetworks com>
Date: Sun, 24 Jul 2005 13:27:31 -0700

Fair enough. I agree, no single product is going to block everything. 

Still a Unified Threat Management (UTM), device like iPolicy Intrusion
Prevention Firewalls, (sorry, required minimal company plug), can go a
long way toward a good defense. Some form of Firewall, and IDS/IPS are
essential on the un-policed Wild Wild Web.

Like you mentioned, I always install Tripwire, or Auditing services on
internal hosts just in case something snuck through. 

Other products like SolidCore attempt to lock the entire OS/Executing
code set, and could be useful as well for critical systems with static
configurations.

And of course there are application specific/data scrubbing systems like
NetContinuum that I would deploy to filter outbound content from web
servers.

After 15 years in networking, I've become OS & System agnostic, I just
try to deploy a combination based on the value of data, the customer
budget, and the potential threats to it. 

Can't always get a Rolls Royce when the budget is for a Kia.

-----Original Message-----
From: Richard Bejtlich [mailto:taosecurity () gmail com] 
Sent: Friday, July 22, 2005 6:23 PM
To: Swift, David
Cc: Mike Barkett; Nick Black; focus-ids () securityfocus com
Subject: Re: Firewalls (was Re: IDS evaluations procedures)

On 7/22/05, Swift, David <dswift () ipolicynetworks com> wrote:
Right up front, I'll admit I work for a vendor, but...

1. There are a growing number Intrusion Detection/Intrusion Prevention
Systems that have integrated firewall.
2. IPS is a significant step in the right direction, and does things a
firewall can't. If you have doubts, try using Firewalker to pinpoint
holes in your firewall, and map network devices PAST the firewall
perimeter. If I can find them, I can attack them. Then craft a few
attacks with Nessus and send a fragmented attack right on through the
firewall at a given target.

iPolicy started a company with the premise that security integration
was
where things were headed. We built a good firewall, that after 5 years
of revisions now has an easy to use interface, AND we incorporate a
good
IDS/IPS engine.

Hi David,

All good points.  If you can get past firewalls using various
techniques, I'm sure others can bypass even your product, right?

This is not an attack against you or any other prevention vendor.  The
unfortunate reality is that at some point a smart, unpredictable
intruder will figure out how to bypass your prevention mechanism. 
Where does that leave an integrated/converged security device?  Will
it have any record at all that it was beaten?  Probably not -- if it
knew what was happening, it would have blocked the attack, correct?

The problem I see with most security vendors is their assumption that
they can even identify attacks properly.  This is a problem because
detection or prevention requires accurate attack identification.  I
gave up on perfect attack detection years ago, but I did not give up
on intrusion detection or prevention as necessary parts of the
security process.  I am glad you and other vendors still work on this
very tough problem!

For my part, I try to identify when my preventative system has failed
via policy enforcement failure detection.  If that doesn't work, I'm
also performing network transaction logging.  Once I know (by
non-technical means, perhaps) that I'm compromised, I have
network-based evidence to guide my incident response and remediation
process.

I don't see do-it-all-in-one security appliances approaching the
problem this way.

I guess my view is biased because I do incident response for a living,
and I constantly deal with failed security mechanisms.  (Unfortunately
for my clients,) I am as busy now (with all the great new gear we
have) as I was seven years ago when I started.

Sincerely,

Richard
http://www.taosecurity.com

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