Firewall Wizards mailing list archives

RE: Re: Anti-Defacement Products...


From: Predrag Zivic <pzivic () yahoo com>
Date: Fri, 19 May 2000 08:17:40 -0700 (PDT)

a late comment but...
Anyway HP VV is good TOS but this will ensure only
that the outside web page is correct. Also without any
PROXY based product (outside to inside proxy) on the
VV itself, you will still remain vulnerable to HTTP
(application attacks, bos etc). However combination of
HP VV with BMC's Safe Passage (no longer supported by
HP) or HP VV with Apache proxy (not officially
released yet by HP) will comply with mcnabb's
requirements.
Another solution to your problem would be to use
combination of F5/alteon/arrowpoint and proxy based
firewall (raptor/gauntlet). where you would terminate
the client connection on the f5/alteon/arrowpoint in
front of the firewall. I like F5 since you can hash
dynamically on proxied (proxiing/proxying...hey
techies change the language barriers:-)) cookies and
http headers if memory serves me ok.
Hope this helps...

Pez

--- fernando_montenegro () hp com wrote:
Hi everyone!

ATTENTION: This message is not supposed to be
marketing drivel. Though I will 
talk about a specific product, I hope the technical
description will merit 
posting to the list.

Using a multilevel OS as a Web server, as Paul
described, is something that we 
have had some success with at HP. One of our better
known products, Virtual 
Vault, is architected almost exactly like Paul
described. The product is based 
on a modified version of HP-UX, so running it is not
totally unlike 
administering a normal UNIX box.

The way that the Virtual Vault (VV) is set up is to
have 4 separate containers, 
enforced by MAC rules (not changeable from a running
process, once "root" is 
disabled and no extra privileges are given to user
accounts):
- System, holds almost all files in the system plus
the running instances of 
most operating system applications.
- Outside, containing ONLY the webserver running
instance and the webserver's 
access log.
- Inside, holds the running instances for some
administrative daemons and the 
customer application, as well some temporary
files/directories.
- SystemHigh, with the audit daemon's running
instance and ancilliary files.

BTW, normal Discretionary Access Controls (DAC, our
familiar owner-group-world 
permission mechanism) still applies, so access is
checked against DAC and MAC 
both.

Should the OUTSIDE compartment be compromised
(through a failure in the Web 
server), the only files subject to change are the
HTTP access logs. Usually, 
the HTML/GIF/JPG/... content will be housed in the
SYSTEM compartment, 
therefore safe from modification by the outside.

The customer application runs in the INSIDE
compartment. While a compromise 
there is worse, it is still limited by the MAC
rules.

Checking MD5 signature on files can be done
on-the-fly for CGI scripts (though 
it will hurt performance) or regularly through cron.

On the downside, it takes some planning to come up
with the proper policies and 
procedures for integrating content, running audits,
... but it is certainly 
within reach of any knowledgeable UNIX shop.

Hope this helps. 

Cheers,
Fernando
--
Fernando da Silveira Montenegro     Hewlett-Packard
Brasil
HP Consulting - IT Security         Al. Rio Negro,
750 - Alphaville
mailto:fernando_montenegro () hp com   Barueri, SP -
Brazil 06454-000
voice: +55-11-7297-4351             #include
<disclaimer.h>


-----Original Message-----
From: mcnabb () argus-systems com
[mailto:mcnabb () argus-systems com]
Sent: Tuesday, March 28, 2000 5:10 PM
To: Kyle.Starkey () msdw com
Cc: mcnabb () argus-systems com;
firewall-wizards () nfr net
Subject: Re: [fw-wiz] Re: Anti-Defacement
Products...


Starkey, Kyle wrote:
I was thinking about defacement the other day
and how to 
help automate a
response to this type of activity.  I understand
that host 
based security
and network based security is the key, but what
about 
response.  I am
looking for a product that could be used to make
sure the page being
displayed was the real page.  Thoughts of
encyting the 
page/code to get a
hash and storing it somewhere inside the
enterprise, 
periodically the
webserver re-calcing the hash on the page stored
locally 
and running a check
against a the stored copy secured in box on the
inside.  I 
would also
envision the automatic posting of the original
source back 
to the webserver
and alerts bieng generated to the security
officer if the 
two hashes did not
match.  Does anyone know of any product that
does something 
similar?  I was
hoping not to have to build this from scratch,
but perhaps 
it will be my
little project.  Any thoughts about this project
or 
software that might
already do this for me would be greatly
appreciated...



1. Use a TOS to create 3 virtual machines: one for
the webserver process,
one for the webpages, and one for administration. 
Make the webpages VM
read-only from the webserver VM.

2. Move all admin utilities into the admin VM.

3. Put the internet network interface in the
webserver VM, and put the
internal LAN network interface into the admin VM. 
If you want, you can
pick certain hosts or subnets on the internal LAN
to be in the admin VM
and send all other internal hosts to the webserver
VM.

4. Use the packet filtering part of the TOS to
prevent the webserver,
or anything that is coming from the Internet from
ever contacting the
admin VM and from ever modifying the webpages VM. 
Note: this will hold
true no matter what machine instructions are
executed in the VM, so you
can open up other services (like ftp or telnet) if
you want.  Or, you
could put these other services in their own VMs.

5. Use the integrity mechanism of the TOS to
verify checksums and security
attributes of the webpage files.  This can be run
automatically at any
interval you need.  If you want to be really
paranoid, set up another VM
for logging and auditing and run everything from
that.  Make the other
VMs visible to the logging VM, but not the other
way around.  Use the
packet filtering on the TOS to limit access to the
logging VM to a single
host somewhere, preferably protected via a VPN and
on the internal LAN.

6. If this is a host with a single network
interface, use virtual IFs
to set up the system so that each VM has its own
virtual network IF and
give each service and VM its own IP address on the
box.




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