mailing list archives
Re: NAT and Web Server Security
From: "Cheryl Goh" <cherylgoh () elock com my>
Date: Fri, 22 Nov 2002 15:28:15 +0800
When NAT is configured at the firewall to allow the public to access a web
server, it is a Static NAT which basically tells the firewall to forward all
traffic destined to the global address of a web server to the internal
address that is unknown to the public. All traffic is passed through and
therefore it will not prevent a hacker from penetrating the server. It will
however hide the ip addresses of all other internal servers, preventing
hackers from accessing those servers directly from the internet.
----- Original Message -----
From: <spato99 () hotmail com>
To: <security-basics () securityfocus com>
Sent: Tuesday, November 19, 2002 6:27 AM
Subject: NAT and Web Server Security
We're about to put a public web server on DMZ sitting behind a Teir 1
firewall and only allow http, ssl to it. We intend to assign a public IP
address to this server and no NAT'ing is done on the firewall for this
address (NATing done for internal network on Teir 2 firewall).
It has been suggested that without NATing, it is possible for a hacker to
compromise this server and pretend to be our company...
1) While NAT address some security issues, doesn't this specific risk
exist regardless of whether NAT is employed or not?
2) If NAT does help in this case, I'd appreciate comments as to how
3) Is there any good reading material on NAT security - specifically,
what it can and can't protect against. The stuff I've read doesn't seem
to talk about NAT in this context.