RE: VMware ESX

["TVB NOC" <tvbnoc () temeculavalleybank com>]

All in all it will depend on your security architecture. And the
implementation strategy you go with... 

Like I said, you don't want to share the physical nics between
environments that are both DMZ and Internal networks. This is why I
stated you should not do vlans between the virtual switch and the
physical switch. Instead have dedicated nics assigned to each server. 

In addition, the VM host using ESX as long as it is not configured to be
routable will not know how to get between the various networks... 

Here is a blurb I found on a separate form... 

http://www.networksecurityarchive.org/html/Firewalls/2005-09/msg00096.ht
ml

Lastly, if you have read the above link, I don't agree with having a
single physical link with multiple servers even if it is dedicated to
DMZ only. I believe each server should have a dedicated NIC connecting
to the DMZ switch. 

thanks... 

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com]
On Behalf Of Tyler Reguly
Sent: Monday, April 21, 2008 8:50 PM
To: security-basics () securityfocus com
Subject: Re: VMware ESX

Greetings,

My Advice could be to *NOT* do this...

This depends, somewhat, on the version of ESX you are running... ESXi
is 32MB and presents a much smaller attack surface that ESX. I would
never advise implementing ESX itself on both the internal network and
the DMZ, but I can't say for sure about implementing ESXi...

However keep this Microsoft Advisory in mind --
http://www.microsoft.com/technet/security/Bulletin/MS07-049.mspx

It is VirtualPC and VirtualServer but think about that.. Admin access
to any single guest, gives you access to all other guests and the
host... Who knows if that exists for VMWare and just hasn't been
stumbled across yet.

Tyler.



On Mon, Apr 21, 2008 at 6:54 PM, TVB NOC <tvbnoc () temeculavalleybank com>
wrote:
> Actually,
>
> I used to work at a company that did it... Because the VMware
instances
> are not aware of each other inside the host, its not a bad solution..
> However, if I were going to implement it, I would not do VLANs and
> Trunking (tagging) between the virtual switch and the physical switch.
I
> would add an additional quad card or other physical network card and
> physically separate the VM host, plugging each isolated VMhost network
> connection them directly into the physical switch...
>
> Hope this helps... sorry for the grammatical errors too...
>
>
>
>
>
> On Mon, Apr 21, 2008 at 5:23 AM, Paul Heywood
> <Paul.Heywood () unitypartnership com> wrote:
> > Hi forum,
> >
> >  we've got a VMware ESX group of servers running on the inside of
our
> network. Our server team want to extend this to include some DMZ
> servers. How vulnerable would this leave the internal network ? Am I
> correct in thinking that if the VMware cluster was hacked, this would
> give them access to the internal network
> >
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