Re: Patching a Firewall

[Robert Mezzone <Robert.Mezzone () PJSolomon Com>]

I really wasn't looking to get into a Unix/Windows war. It was more of a
theoretical question.

Can a Unix a box be hardened more than a Windows box, I don't know since my
Unix exposure is minimal, but there are a lot of things that can be done to
a Windows machine to lock it down pretty tight. Can it be hacked, probably,
but I would imagine anything can given enough time.

I guess you are right about the Firewall accepting connections to itself,
although I would think it would be slighty more secure when there is no
remote administration taking place. Then again I could be wrong.

You're not the only person to make this mistake but not all investment
banking firms deal with money.

Thanks for your comments.

Robert


-----Original Message-----
From: Jimi Thompson <jimit () myrealbox com>
To: Robert Mezzone <Robert.Mezzone () PJSolomon Com>;
'security-basics () securityfocus com' <security-basics () securityfocus com>
Sent: Sun Sep 14 14:04:48 2003
Subject: Re: Patching a Firewall

Robert,

Item 1 - I would never run Windows as a firewall simply because of 
the extreme difficulty in hardening the OS to prevent it from being 
exploited.  I have heard of this being done, but I've never observed 
it in a reputable shop.  Most places either use a device that is 
specifically a firewall or a hardened *nix OS (i.e. Solaris, Trusted 
Solaris, Trusted FreeBSD, NSA Secure Linux, Bastille, etc.).  The 
reason for using a nix OS is so that services which are not needed 
can be removed from the box without causing a major disruption to the 
OS.  Think of what would happen if you tried to un-install NetBIOS 
from Windows.

Item 2 - If your OS on your firewall has a vulnerability, your 
firewall itself is vulnerable.  If I can get your OS to cooperate and 
give me "root" or "Administrator", I can change your firewall rules, 
logging, user accounts, etc. to suit myself.

Item 3 - Your firewall, for management purposes, probably accepts 
connections to itself.  The question then becomes where does it 
accept connections from and, if you are a hacker, how can I spoof 
that.  ANYTHING that's not physical layer can be spoofed and even 
that's not a guarantee that someone sneaky hasn't installed a device 
somewhere to trip you up.

I notice from your email address that you are with an investment 
banker.  That means you deal with money.  Any time cash is involved, 
especially transferring cash electronically, your level of paranoia 
should be very very high (like almost ready to cart you off in the "i 
love me jacket").  Never mind the SEC regulations.....

2 Cents,

Jimi




At 8:15 AM -0400 9/12/03, Robert Mezzone wrote:
> I want to start off by saying my Firewall is fully patched. That being said
> my question is...
>
> Is it a big security risk if the OS (say Windows) running the firewall box,
> is not fully patched? My reasoning that it isn't is because the firewall
> should be configured to drop any connections to itself. Or being the
> firewall has to at least initially accept the packet in order to inspect
it,
> enough to exploit a vulnerability.
>
> Robert
>
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Are you prepared for the next Sobig & Blaster? 
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