RE: Security and VPN

From: Russell Butturini (rbutturini@tcstech.com)
Date: Wed Jun 20 2007 - 09:36:46 EDT


We work with a lot of customers who need to have the connectivity options
for using a VPN client from home, but have a limited budget to work with and
can't afford network upgrades/reconfigurations/more appliances to
accommodate this. The procedure I usually follow is two steps:

1. Each machine is brought in and "sanitized" (i.e. reformatted and data
reloaded if the employee will allow it, or at the least given thorough
spyware, virus, and Trojan scans), and then has all available MS and
manufacturer updates loaded on it.

2. Give clients connecting over the VPN a particular block of DHCP
addresses, and then block traffic to internal servers we don't want accessed
across the VPN from those IPs.

Are there better solutions? Yes. Unfortunately "you gotta do what you gotta
do" sometimes. We try to make the employees bring in the remote PCs on a
regular basis for checkups, but this is not always realistic (i.e. people
are stubborn :-) ).

On a related note, does anyone have reccomendations for a good SSL VPN
appliance? We have been testing the Sonicwall appliance in house and it has
been less than impressive so far.

 
-----Original Message-----
From: listbounce@securityfocus.com [mailto:listbounce@securityfocus.com] On
Behalf Of The Sun
Sent: Tuesday, June 19, 2007 9:44 PM
To: Andrew Vliet; Sohail Sarwar
Cc: Philip Cox; pen-test@securityfocus.com
Subject: Re: Security and VPN

Andrew said:
I would not be putting VPN clients on employee owned systems.

I would agree with you Andrew.
I also suggest one more option - SSL VPN.
So far in this thread, everyone has been focusing on IPSEC VPNs only.
Many organizations are moving towards SSL-VPN to get more granular control.
For instance, some SSL-VPN solutions can give access to web applications,
file sharing and RDP without a client to be installed - you still would need

some activeX or java applet and a browser.
You could then allow third parties to only some of these and at the same
time allow full network access (all TCP/UDP protocols supported) to trusted
users from trusted devices only, if required.

----- Original Message -----
From: "Andrew Vliet" <Andrew.Vliet@lvs1.com>
To: "Sohail Sarwar" <ssarwar@ecredit.com>
Cc: "Philip Cox" <Phil.Cox@systemexperts.com>; <pen-test@securityfocus.com>
Sent: Wednesday, June 20, 2007 4:12 AM
Subject: RE: Security and VPN

Sohail Sarwar,

2 factor authentication is great, but personally I would go one further
than Philip. I would not be putting VPN clients on employee owned
systems. Yes, I say no clients - period. Too many variables - too
insecure.

I understand that it's expensive, but none the less, I would either put
in a Citrix farm or purchase dedicated, company owned and maintained
machines for your employees to use at home. Add the VPN client to these
machines company owned machines.

When considering the speed and volatility of trojans and viruses these
days; Adding VPN to an unknown, uncontrolled, insecure client - even
after adding Antivirus checking, etc - is simply asking for trouble.

Of course, we haven't even touched on the legal and privacy implications
of the company having direct access to an employee's personal network,
all computers there-in and visa versa.

VPN on employee machines == bad idea - don't do it. Provide Citrix or
dedicated, managed machines.

Regards,
Andrew Vliet

-----Original Message-----
From: listbounce@securityfocus.com [mailto:listbounce@securityfocus.com]
On Behalf Of Philip Cox
Sent: Tuesday, June 19, 2007 9:25 AM
To: 'Sohail Sarwar'; pen-test@securityfocus.com
Subject: RE: Security and VPN

> -----Original Message-----
> From: listbounce@securityfocus.com
> [mailto:listbounce@securityfocus.com] On Behalf Of Sohail Sarwar
> Sent: Monday, June 18, 2007 6:08 AM
> To: James Patterson; pen-test@securityfocus.com
> Cc: holstein.robert@bls.gov
> Subject: Security and VPN
>
> Hi there,
>
> I just wanted to put this out there. How secure is VPN.
> Meaning, if my users take home the client and install it on their
> desktop at home, and connect to the corporate network and production
> network, wheat are we really looking at. Are they secure or not.

Just given this decription, I would say NO, they are not secure.

> Has anyone been through this. Any one give home users a list of

> requirements that they must have before vpn can be offered to them ?
>
> Should there be some type of desktop policy installed on their
home
> computer, just to protect the company network ? Any help and guidance

> would be great

My recommendation would be to...

1. Require 2 factor authenticaiton for VPN access 2. Ensure that the VPN
server/environment performs some type of system validaiton prior to
letting the system have full access to the internal network. This
typically includes verifying a patch level and that anti-virus is
installed and up-to-date 3. Use the VPN server to restirct where the VPN
client can connect 4. Review the VPN server logs for who is accessign
the server and from where

Just my $.02

Phil

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