This is part of a detailed look at the recently published
Discussion Draft of the Preliminary Cybersecurity Framework (PCF). The NIST
Information Technology Laboratory (ITL) published this and supporting
documentation to their web site during the week of August 28th in
order to allow for public comments and preparatory work for the 4th
Cybersecurity Framework Workshop in Dallas, TX next week. The other posts in
the series are:
In the introduction to the Discussion Draft the crafters
asked a series of questions that they want reviewers to answer. The whole point
of releasing this Discussion Draft is to provide a basis for the last Workshop
to finalize work on the Preliminary Framework. The next document we see from
the NIST authors will be the version of the Preliminary Cybersecurity Framework
that will be sent to the President. So the answers to these questions posed on
page i will almost certainly provide the direction for discussions at the
Workshop and the final edit of the ‘preliminary’ document headed to the
President.
The question I would like to address in this post is:
Is the Discussion Draft presented
at the right level of specificity?
To completely answer this question I would have to look at
all of the Subcategories and that would just be too time consuming for this
blog. So what I will do is look at a couple of random subcategories to see if
the specificity of needs to be adjusted.
Identify
legal/regulatory requirements
This is the 3rd subcategory found in the Identify
function and the Governance Category. The purpose of the Governance Category is
to (pg 15):
Identify the policies, procedures,
and processes to manage and monitor the organization's regulatory, legal, risk,
environmental, and operational requirements.
The Informative References listed for this Subcategory are:
• ISA 99.02.01 4.4.3.7
• COBIT MEA03.01, MEA03.04
• ISO/IEC 27001 A.15.1.1
• NIST SP 800-53 Rev. 4 -1 controls
from all families (except PM-1)
Unfortunately, the first three references all require the
references to be purchased; $215 for the ANSI document, $175/book for the COBIT
5 documents, and CHF (Swiss Franks) 134,00 for the ISO/IEC document. Those are
not unreasonable prices from a corporate point if view, but well outside my
budget as a blogger. So, let’s assume that one or more of them will provide
listings of various regulatory programs that might apply to cybersecurity
operations across a wide variety of organizations.
The NIST document is free of charge, but it does not provide
any specific information about the various legal or regulatory requirements
that might apply to high-risk critical infrastructure facilities.
So why doesn’t NIST just provide a listing of such
regulatory programs in an appendix to the Cybersecurity Framework? I would bet
that the folks at NIST decided to let the ISA and ISO organizations worry about
keeping their documents updated for changes in the regulatory landscape; they
are going to be doing that work in any case. That way NIST (or DHS, or whomever
is going to be maintaining the final version of the Framework) will not have to
fund an on-going operation to keep this part of the Framework current.
Characterize Detected
Events
This is the second Subcategory of the Anomalies and Events
Category of the Detect Function of the Framework Core. Its complete description
is (pg 21):
DE.AE-2: Characterize
detected events (including through the use of traffic analysis) to understand
attack targets and how a detected event is taking place.
This was not quite selected randomly as I was looking for a
subcategory with only one Informative Reference listed, and obviously the free
one. That reference takes us to SI-4 (Control Number SI-4, Information System
Monitoring, on pages F-219 thru F-223 of the NIST SP 800-53. While that
discussion is fairly extensive, it focuses on the methods of detecting attacks
and indicators of potential attacks; not on characterizing the events detected.
Update Response Strategies
This is the second Subcategory of the Improvement Category
of the Respond Function. The title is all of the information provided in the
Subcategory (pg 23), but it does provide an Informative Reference to NIST SP
800-53 IR 8; Incident Response Plan (pgs F-106 thru F-107). There is a single comment
in that reference that applies to this particular sub-category (IR-8d):
“Updates the incident response plan
to address system/organizational changes or problems encountered during plan
implementation, execution, or testing”.
That is a concise description of the events that would be
expected to trigger an incident response plan update. Assuming that the
organization was capable of constructing a reasonably successful incident
response plan, this statement would probably suffice to outline what is needed
to keep it a living document.
Adequate Specificity?
Using these three subcategories as a measure of the specificity
of the Framework Core begs a very important question; who will be using the
Framework Core? If an organization has the in-house (or consultant) expertise necessary
to set up a cybersecurity apparat, then the information provided in these three
examples should provide enough guidance. If there is not that basic level of
cybersecurity expertise available, then NIST would be hard pressed to prepare
an encyclopedic document adequate to the task.
It must be remembered here that the Cybersecurity Framework
is envisioned to be an aid to focusing management on conducting a risk
management evaluation of the cybersecurity status of an organization and making
appropriate adjustments based upon their assessment of the risks and
cost-benefit analysis of the situation. This is not intended to be a government
mandated set of security standards against which the cybersecurity program of
an organization is measured.
Whether or not that differentiation of the goals of the
Cybersecurity Framework is the appropriate way of addressing cybersecurity for
critical infrastructure organizations is a completely separate question.
No comments:
Post a Comment