RE: [PEN-TEST] Detecting the presence of a firewall

["Geoghegan, Glyn (ISS London)" <glyng () iss net>]

nmap scans of poorly configured FW-1 boxes may also show UDP/53 and TCP/53
as 'closed' on the firewall and protected hosts, due to DNS lookups being
permitted in the 'Policy Properties' dialogues.

Whilst this is a relatively old mis-configuration (dates to early 4.0
deployments), it's still fairly common, and provides opportunities for an
attacker to probe hosts behind the firewall, or to abuse those hosts through
trojans or tunnelling.

http://www.phoneboy.com/faq/0131.html

G

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-----Original Message-----
From: railwayclubposse () hushmail com
[mailto:railwayclubposse () hushmail com]
Sent: 14 May 2001 17:44
To: PEN-TEST () securityfocus com
Subject: RE: [PEN-TEST] Detecting the presence of a firewall


For Checkpoint, use nmap and do a TCP and OS detection scan. If they are 
doing one-to-many NAT the machines will be detected as "behind a Checkpoint 
Firewall-1 4.1 SP2 Server" or whatever. The firewall itself is likely to 
have some combination of  TCP ports 256-259, 264-265 open for management,
auth, key exchange, etc. 

> -----Original Message-----
> From: priya subramanian [mailto:pentesting () YAHOO CO IN]
> Sent: Monday, May 07, 2001 5:11 AM
> To: PEN-TEST () SECURITYFOCUS COM
> Subject: [PEN-TEST] Detecting the presence of a firewall
>
>
> Pl clarify the following
>
> 1. Are there any means of detecting the presence of a
> checkpoint firewall at a company's premises,  from a
> remote location.
>
> 2.Knowing one interface of the firewall machine, is it
> possible for me to find the ip addresses of the other
> interfaces.
>
> Kindly reply at the earliest.
>
> Priya
>
> Free, encrypted, secure Web-based email at www.hushmail.com
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