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ITS 3050 - Security Policies and Auditing
Security Policies and Implementation Issues
Chapter 6, IT Security Policy Frameworks
Chapter 7, How to Design, Organize, Implement, and Maintain Security
Policies
Objectives:
This lesson covers chapters 6 and 7. It discusses areas of
IT security policy frameworks, factors to consider when creating them,
implementing them, and maintaining them. Objectives important to this
lesson:
- IT security policy frameworks
- IT program framework policies
- Business factors relating to building a policy framework
- Information assurance factors to consider
- ISS factors to consider
- Best practices
- Designing policies
- Contents of a policy framework
- Implementing policies
- Policy change control
- Maintaining policies and standards
- Best practices
Concepts:
Chapter 6
This chapter begins with a definition of an IT security policy
framework. Unfortunately, it is only a list of components found in a
framework, so it would tell you little if you do not understand the
items listed there. Before continuing, review lesson 7 and compare it
to this week's list of components.
- Policies - rules about the conduct of our organization with
regard to particular actions (we will limit ourselves to particular
models chosen by the IT department); how we will approach the
expectation
- Standards - a method or process that may be procedural or
technical (orders are to be placed by approved requesters within each
work area); what steps are to be followed to assure general compliance
with policy
- Baselines - standards from which other standards are
developed; we might have a baseline standard that all PCs will come
from one vendor contract with a minimum feature set, and specific
standards for advanced models for IT system developers
- Procedure - a detailed set of steps to follow to be in
compliance (requests are to be made to your manager, who will forward
approved requests to your authorized requester); variations or
limitations that apply to specific work areas, to be followed if they
apply to your area
- Guidelines - a suggested addition to any of the items above
that is recommended but optional (submit your requests two weeks before
the end of a quarter to allow processing time); do this to make it work
better
- Taxonomy - a set of definitions of how terms are
used in our organization; this can also mean naming standards for
objects in our organization, used in Active Directory or a management
program; naming systems can be based on location, use, categorization,
department or division ownership, or other concepts important to your
organization
The author has thrown in some new ones. I made them bold
in the list above. His comments on page 144 about growing a library of
these documents being like growing a tree is a pretty good analogy.
Like a tree, the parts of your business need to grow, to reach maturity,
to produce fruit or nuts or seeds, and to be cut away
to make room for new growth when they are no use any longer. The pieces
of your policy framework should be expected to do the same. We need new
rules about new products, new problems, and new changes
to the environment.
The text talks about risk again for a bit. The author defines
two phrases that may be misunderstood:
- Risk appetite - The upper limit of risk that is
acceptable in pursuit of a goal
- Risk tolerance - The amount of variance in risk
that is acceptable to an organization
Risk appetite is a measure of the greatest risk
that is allowed to be undertaken. Most organizations are cautious about
risk, if there is a significant impact. Risk tolerance is a
measure of the difference between the highest risks, lowest
risks, and average risks in an organization. No one minds low
risk, but risks that are too high, too different from our
standard operation, will cause too much variance in the performance of
the company.
The next topic is called by two names: program framework
policy and information security program charter. Both
phrases are almost indecipherable, so let's see what the author means.
The word program, which appears in both names, refers to a
broad authority to make rules and procedures regarding
information security that must be followed by all employees in the
organization. The word charter in the second phrase also refers
to the authority being granted to the people managing this
program. Four common names for the officer who runs such a program
appear at the top of page 147. Such authority must be granted by the
legitimate owners or operators of the organization. We have already
been sold on the idea of a framework containing all the concepts in the
list above. The program framework policy, or program charter, is meant
to be an even larger concept, one that establishes the legitimate
rights of the office administering it.
The text lists four areas of concern within the
program framework policy. Don't be confused, it still includes
all the bulleted items above. It also includes these:
- Purpose and mission of the program - The
text discusses this area with terms that sound unrealistic. Yes, the
program should support the goals of the organization. How does
protecting our customers' data conflict with the goals of any
organization. The purpose is to perform the basic functions of
an information security department, and to protect our assets.
Alignment with the mission goals of the organization is more of a
political statement than a useful one.
- Scope of the program - A discussion of the scope of
the program depends on what our assets are, what our budget is, and how
we decide which risks to protect ourselves from. There will never be
enough money to do everything we want to do, so we have to live within
our means.
- Responsible parties who will implement the
program - This area makes it clear who has what responsibilities with
respect to carrying out the procedures, notifying staff of policy, and
making sure that these people do their jobs.
- Compliance management - The program requires that
people follow the rules, and must also allow for monitoring performance
for compliance and for violations. It must allow for policies to be
created by the proper part of the organization (such as Human
Resources) with regard to discipline for single, multiple, and repeated
violations.
The text moves on to discuss well known framework models
(security management models) that are often chosen by
organizations as the basis for their own frameworks. To put this in
perspective, imagine three phases of a project to develop your
security management standards, as described by last year's text:
- First, select a security management model that fits your
organization's needs and goals.
- Second, write your own security framework document, a plan that outlines the work needed to adapt the model to the realities of
your organization.
- Third, create the security blueprint, which is a working, operational document. It describes
how your organization will meet
each applicable requirement of your security model, through the goals
that are established in your framework.
So, that means you need to create the framework and the
blueprint, but your first goal is to select
a model that makes sense. You see what I mean about different
terms in different books? They really mean the same things. You just
have to get an idea about the concepts first to see that it is the same
message.
How do you select a model?
Sometimes, a model has been selected
for you by another part of the organization (upper management)
and you simply have to use it. The good news is that whichever model
was chosen, it will probably work after being customized into the
blueprint for your organization.
- COBIT
(Control Objectives for Information and Related Technology) - not
discussed in detail in the text; follow the link to the left to see
details
- ISO 27000 Series
(International Organization for Standardization) - see the list of
topics in document 27002 on pages 150-153
- NIST (National Institute of
Standards and Technology) Models
- see the brief discussion on page 153, and the table on pages 154-155,
principles in NIST Special Publication 800-53
- ITIL (formerly
Information Technology Infrastructure Library, now just ITIL) - not
mentioned in this text; see the ITIL official site for more
information; it was created by the British government and has become a
world wide standard
- The image on the right links to another standard, from a
hardware vendor. You may find that the model offered by Cisco
explains the concepts more clearly that the web site above.
The text continues with a section on standards. Note
that the definition at the top of of this web page only says a standard
contains steps to follow to be compliant with a policy. The policies
are meant to be general, and related standards are meant to be more specific.
This often means that standards need to be:
- clearly written (so people will understand them)
- repeatable (so the same results can be expected)
- pursuing a known goal (part of the policy)
- applicable to the people following them (so those
people can actually perform the steps)
Page 157 discusses two types of standards:
- Issue specific standard - This kind of standard can
relate to new technology or a new situation.
- Issue statement - This part of the standard would
commonly define terms used to discuss it, define what the perceived
risks might be, and what employees are expected to do.
- Organization position - Why does the organization want
us to follow this standard.
- Applicability - What is the scope of the policy and
this standard? Specific rules about how to apply the standard.
- Roles and responsibilities - If the standard requires
approvals, who approves and who makes requests.
- Compliance - This is the part that tells us what people
are not allowed to do, how they will be monitored, and what discipline
is to be expected for noncompliance.
- Points of contact - Who to ask if you have questions,
where to find this standard in the library, who to ask for help if the
standard does not work.
- System specific standard - A standard for a system
(like a network, or an application with many users)
- Who is allowed to use this system?
- Are only specific users allowed to modify it? If so,
who are they?
- Are there firewall rules, domain rules, or port rules
for this system? This is especially important for public facing systems.
- Are users allowed to access the system remotely? Must
they use a VPN to access it?
The text continues with a discussion about procedures
and why we need them. Typically, a procedure is used when a standard
has a large scope, and it must be followed differently by people in
different jobs, or who are operating in different countries. The things
a standard tells us to do usually are smaller in scope than the
standard that it modifies, because of job duties or because of local
regulations that differ from place to place.
Guidelines are mentioned briefly. The text observes
that guidelines start out as suggestions, which often become standards
if they work out well.
The text reminds us that policy frameworks, like anything else
in business, may be affected by their cost and by the impact
of their controls on employees, customers, and business
processes. There is no way a program that is too costly can be
adopted. Likewise, we cannot introduce security in a way that keeps our
employees from working or keeps our customers from doing business with
us.
The text reviews the five pillars of Information Assurance,
reminding us that our policy framework must support all of them. They
were discussed in lesson 1:
- Confidentiality - we do not allow access to any
resource unless there is a reason for that access
- Integrity - making sure that no one changes data who
has not been authorized to do so
- Availability - data must be available to authorized
users when they need it
- Authentication - the security needs of the system
must be matched by the level of confidence we have in a user's identity
- Nonrepudiation - tracking of events and files must
prove that a particular user took action, authorized access or payment,
or simply was on the system
The text amplifies on this theme a bit, listing some other
risks that our framework should guard against:
- Unauthorized access
- Unauthorized use
- Unauthorized disclosure
- Disruption of services
- Destruction of assets
The text also offers some best practices regarding policy
frameworks:
- Let the staff know about the framework - no one follows
rules they do not know about
- Remind staff about the framework - make people aware that
security is also up to them
- Select a framework model that fits your organization, then
customize it as needed
- Learn from the mistakes of other companies - I recommend
that you regularly read Brian Krebs' website, Krebs on Security for news
and analysis
Chapter 7
The chapter begins with some advice about writing all of our
security documents clearly. It implies that we should be using a middle
of the road grade level for our documents, making them easy for most
people to understand. I am not surprised that the author finally gets
around to saying that we should answer the six basic questions I
mentioned in the ITS 421 class this term. Let's use the same reference:
This is another way of looking at
the rules you need to implement on your network. Explain them.
A good idea is to memorize a line from Rudyard
Kipling about six honest serving
men:
I keep six honest serving-men
(They taught me all I knew);
Their names are What and Why and When
And How and Where and Who.
(The rest of the poem is not important in this context. Yes,
you should read poetry. And science fiction, and detective stories, and
lots of other things.)
- Who does this policy affect?
- Why is the policy needed?
- What is the policy about? What are we
allowed to do and not allowed to do?
- When is the policy going into effect? When
are we subject to it, and when are we not?
- Where does this policy apply? Only at home? Only at
remote locations? Everywhere?
- How will it be monitored? How will
compliance be measured? How do we request exceptions or report problems?
The author takes a moment for another point before continuing
on this topic. He quotes another text on page 176, to illustrate the
idea that some security framework models use an Architecture
approach. This is the approach taken by the Cisco model that is
linked above. So what is architecture, with regard to frameworks? If
you search the web for an answer, you will find other definitions than
the one the author intended, so let's examine his concept.
Consider the diagram on page 177. It shows a classic four by
four grid. The x axis shows increasing service standardization from
left to right. The y axis shows increasing service integration from
bottom to top.
High Service Integration |
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Low Service Integration |
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Low Standardization |
High Standardization
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In the chart above, I have shown the same data, but added some
color. The progression from low to high service integration
(purple scale), considering only that change, takes us from a diversified
model to a coordinated model.
- Diversified - this model does not share data well
from one entity to another, systems are independent and require
knowledge of each one to support them
- Coordinated - this model can share data across the
enterprise, making it a better solution; this model is achieved by more
standardization
The progression from low to high service standardization
(blue scale), considering only that change, takes us from a diversified
model to a replicated model.
- Diversified - this model does not use the same
services from one entity to another, services vary across locations and
systems
- Replicated - this model has common services across
the enterprise, providing a common, more familiar interface, making it
a better solution; this solution is achieved by more central control
of services
The last option includes both levels of integration, taking us
to a unified model.
- Unified - this model has the benefits of both of the
better models, it can share data across the enterprise and it has
common services across the enterprise, making it the best choice
The text presents a long list of principles on pages
178 and 179 that should guide us in making policies. They are guides,
not rules, so we should use our judgement when making policies which
become rules. Some highlights from the list:
- Accountability - Make it clear whether a person is
responsible only for his/her own actions, or for those of all
people below him/her in the organization chart
- Awareness - Tell people what the rules are, remind
them from time to time, and make the rules easy to find on the
organization's internal web site
- Multidisciplinary - Tell people in every
type of job what they need to know to do their job correctly in
compliance with policies
- Integration - make sure your policies support
each other and do not contradict each other
- Defense in depth - make sure that we have multiple
layers of defense, and that controls are different from one
layer to the next, so a particular exploit will not be able to
penetrate all layers of defense
Several other principles are valuable as well, so you
should read all of them. Let's have a discussion about them on
Canvas this week.
A classic point of confusion is covered on page 180 and 180.
The text presents two different methods of categorizing security
controls. Remember that any control will fit in both
categorizations, not just one of them. They were also mentioned in
chapter 2.
Categorizations based on control type (and who would
administer it):
- Physical controls -
These include any physical barrier, like a locked door or a fence, as
well as security cameras and guards
- Administrative controls
- These include the procedures
to create security policies and the security
policies themselves. Security policies are rules about
"the actions that users may do,
must do, and must not do". I have
reworded it here, because "cannot" and "must not" do not mean the same
thing.
- Technical controls
- Actions that are performed by devices
(technical solutions), such a firewalls denying packets.
Categorizations based on the function of a control:
- Deterrent
controls - used to discourage
attacks; applied before an
attack; example: warning
attackers that we are protected
- Preventive controls
- used to prevent attacks;
applied before an attack;
example: using a firewall to block
traffic for specific ports; these controls are typically automatic
controls
- Detective controls
- used to detect an attack or intrusion;; applied during an attack; example: using a Intrusion Detection System; these
controls are typically manual controls
- Corrective controls
- used to reduce damage and restore to service; applied after an attack; example: using an emergency cleaning program on a USB
memory stick, so that a computer can be usable
- Compensating
controls - alternative controls that are used when normal controls are
not possible; applied during
an attack; example: disabling switch
ports to isolate devices or LAN segments
- Mitigating
controls - any type of control may be a mitigating control if it finds
or notices errors and presents
a method to correct them
- Recovery controls - controls that restore service to
its state before the attack
The highlighted categorizations above are the ones your text
does not mention.
Moving ahead to page 185, the text begins several pages of
sample templates. There is a template for a policy, a standard,
a procedure, and a guideline. If your employer has been
using such documents for a while, there is probably an enterprise
standard you would follow. If this is not the case, the samples
offered in the chapter give you an excellent place to start making a
template for your organization. Let's do one or two of those as an assignment
this week. The best way to provide a job aid like this is to provide
both the template and an example of your enterprise documentation that
uses it. As an assignment, follow the template for a policy that starts
on page 185, and write a policy that would make sense to you.
The text begins a new section on page 190 about creating
and implementing policies. It lists four steps, but it expands on
each of them.
- Building consensus on intent - This means to consult
the various authorities in your organization about the policy itself.
What is the policy about, and why are we writing it?
These questions must be answered before you can begin to write it. The
authorities are approving the concept of the policy at this stage, not
its final version.
- Reviews and approvals - In a sense, this is the same
as the step above, except that it happens after each draft of
the policy document. Note the list on page 191 of four types of staff
who should review the policy for its accuracy and compliance with other
policies and procedures in the organization:
- Technical personnel
- Legal authority
- Human Resources
- Audit and compliance staff
- Publication - There should be a library of
some sort, whether a shared folder in the file system, an intranet web
site, or another form of data sharing within your organization. The
text mentions placing the original documents in the library with links
to PDF copies. In practice, it is often best to keep the
originals off line, and to store PDF versions as the ones the general
staff may access. In a well run library, there will be follow up dates
for reviews, revisions, and eventual retirement of policies.
- Awareness and training - As we have discussed
before, the organization has an obligation to inform staff
about new or changed policies, to keep them aware
of continuing issues, and to train or educate staff as
needed to perform their jobs properly under such policies. Training
means to show someone how to do a job. Educating means to teach someone
how a thing works, so they might think for themselves as needed, and
continue to learn about the tools in question.
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