RE: RE: In defense of non standard ports

["Bill Royds" <bill () royds net>]

A good firewall should have the capability of allowing its firewall rules to
label traffic through a non-standard port as HTTP (or HTTPS) and properly
analyze it. So, even though it is a port other than 80/443, there should be the
same rules and restrictions applied to it as for normal HTTP.
  For example, some application firewalls allow on to have a IP specific rule
such as
> From internal:any to specifichost(or subnet):1234 allow HTTPS

This would be set on the outgoing firewall and only allow approved traffic to
that host and port.

Creating this rule would then follow the standard policy process for allowing
outgoing traffic.

It is not the non-standard port that is the problem, but the concept that one
should somehow ignore policy because of their use.

As a postscript, when I managed a corporate firewall, I found that a number of
sites and applications were trying to pass arbitrary traffic through HTTPS by
just believing that it would not be examined by an application proxy more than
checking the headers. Our particular firewall (Symantec SEF) actually had an
HTTPS proxy and complained that the handshake was not correct and refused it. 



-----Original Message-----
From: firewall-wizards-admin () honor icsalabs com
[mailto:firewall-wizards-admin () honor icsalabs com] On Behalf Of Behm, Jeffrey L.
Sent: Monday, January 23, 2006 10:25 AM
To: firewall-wizards () honor icsalabs com
Subject: [fw-wiz] RE: In defense of non standard ports

On Friday, January 20, 2006 8:02 PM, Hawkins, Michael so spake:
> Using non standard ports actually makes it easier to control 
> and maintain a strong security policy.

For perhaps a few/limited number of instances...see below

> Let's face it, port 80 is now one of the most insecure holes 
> that you punch through your firewall.

How does running the same traffic across another port automatically make
it more secure? Also, we don't just have it punched through...one must
go through a proxy, and they do not have
direct-through-the-firewall-port-80-access. Explaining the reasoning
behind that to most vendors is many times an exercise in futility.

> All those hard earned dollars needed to control content and you
> are never able to get completely on top of it.
>
> Along comes a real time trading application. Financial services
> company X wants to use financial services company Y's application.
>
> It's so much easier to have a registered port, a short list
> of host IP's A,B and C and a strong security policy document
> and X is now much happier opening up registered port to 
> hosts A,B and C.

Again, why is traffic on port 12345 automatically more secure than going
across port 80? I'd argue that since we block *direct* port 80/443
access (you have to go through the proxy) that port 80/443 web traffic
is more secure than running on some other port that doesn't go through
the proxy. It also makes it more difficult to know how much actual web
traffic is going on, if it is now running across multiple (non-standard)
ports. 

Additionally, if it's only one company connecting to one other company,
than running traffic on a different port could be manageable. But,
extrapolate that out to thousands of companies connecting to thousands
of companies and how do I effectively manage that? What if two (or
twenty, or two hundred) external companies that I want to connect to all
choose to run their web app across the same non-standard port? Then, I'm
right back to the port 80/443 scenario again. It's only a matter of
time...why not just use port 80/443, since it's all just web traffic
anyways...Aren't those the registered ports for web traffic?

> No content filtering needed. No megabucks involved. No content
> filtering overloading your http processes.

It's web traffic...I'm still content filtering it. Perhaps my OP wasn't
clear. I'm talking about developers moving *web* traffic off the
standard 80/443 ports. 

> I am NOT defending shoddy developers that don't know a port
> from a dock.
A port? Someone going on a cruise? Sign me up...

> But ports are part of IP and I'm glad there are 65535 of 'em!
>
> Mike H 

Hopefully, I've made my question of *web* traffic being moved off the
standard ports a bit more clear ...I'm still interested to hear what
wording you use when you talk to vendors about why they chose to run web
traffic off these ports. Oh, yeah, and I'd like to hear what their
responses are, too.

Jeff

_

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