RE: [fw-wiz] terminal services

From: Marcus J. Ranum (
Date: 01/28/03

To: "R. DuFresne" <>, "Paul D. Robertson" <>
From: "Marcus J. Ranum" <>
Date: Tue Jan 28 21:08:01 2003

R. DuFresne wrote:
>Which seems to make a strong casepoint for the hardening of exposed hosts
>and the continued need for well defined security perimiters at this point
>in time still <security basics 101?>.

It's pretty much security 101 as you say. I think the most frequent
recommendation I've written in consulting reports reads something like
"Establish a list of Internet-accessible perimeter systems. On those systems,
establish a list of Internet-accessible applications based on the boundary
firewall's 'permit' rules. For each of those applications, maintain a list of
the software packages that provide the service, and the revision level of
each package. Assign someone to perform a periodic check on each
package by revision level, to install security updates as necessary. Ideally,
this process should be as automated and proactive as possible."

"Geeze! That's a ton of work!" is the usual response. Yeah, well, it is.
But it's easy to fix: minimize services, minimize software release
dispersion (common release) and minimize administrators. Oddly
you'll find that security almost always improves as a result.