RE: VPN's - Firewall's and Security

["Larry Thompson" <lthompson999 () comcast net>]

Sounds like you are terminating the VPN at your PIX F/W. This is not good
practice. You should terminate the VPN in a separate DMZ for VPN only and
then have the F/W apply the normal filters. If this is not possible, apply
the filter rules on the same interface as the crypto map to block port 135
outbound as well as the ICMP "nichi" problem (looks like a smurf attack).

Larry Thompson, CISSP, GSEC
Encryption Manager


-----Original Message-----
From: Christopher Joles [mailto:CJoles () proteabhs com]
Sent: Tuesday, August 26, 2003 11:09 AM
To: security-basics () securityfocus com
Subject: VPN's - Firewall's and Security


Good Day All!

I'm looking for design advice.

Currently, I have a network that is protected by a Cisco PIX 515 =
firewall.  We have it configured to protect our internal network along =
with supplying access to our DMZ which holds our email and web servers.

My concern arises from the spread of the blaster worm.  Currently we =
give a couple employees (the boss, the CFO and myself) VPN access from =
home.  In this scenario, the bosses home computer was compromised by the
= blaster worm and luckily for me, he was on vacation in Germany at the
= time.  If he wasn't, he most assuridly would have made a VPN
connection = and the lovely blaster worm would have gotten through our
defenses.  = Keep in mind, I had applied the MS patch to our servers and
= workstations, however, it would have still gotten "inside".  How can I
= redesign my network to either firewall the VPN connections or at a =
minimum filter them.

Thanx for your opinions in advance!

Christopher J. Joles
Chief Information Officer

PROTEA Behavioral Health Services
187 Exchange St.
Bangor, ME 04401
Phone: (207)992-7010 Ext: 245  Fax:(207)992-7011



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Attend Black Hat Briefings & Training Federal, September 29-30 (Training), 
October 1-2 (Briefings) in Tysons Corner, VA; the world's premier 
technical IT security event.  Modeled after the famous Black Hat event in 
Las Vegas! 6 tracks, 12 training sessions, top speakers and sponsors.  
Symantec is the Diamond sponsor.  Early-bird registration ends September 6.Visit us: www.blackhat.com
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