(ISC)2 CISSP Certified Information Systems Security Professional Official Study Guide. Mike Chapple

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(ISC)2 CISSP Certified Information Systems Security Professional Official Study Guide - Mike Chapple

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terms and elements are clearly related, as shown in Figure 2.2. Threats exploit vulnerabilities, which results in exposure. Exposure is risk, and risk is mitigated by safeguards. Safeguards protect assets that are endangered by threats.

Schematic illustration of the cyclical relationships of risk elements.

      The general idea of a threat-based risk assessment was discussed in Chapter 1. The discussion of risk assessment in this chapter will focus on an asset-based risk assessment approach.

      Asset Valuation

      An asset-based or asset-initiated risk analysis starts with inventorying all organizational assets. Once that inventory is complete, a valuation needs to be assigned to each asset. The evaluation or appraisal of each asset helps establish its importance or criticality to the business operations. If an asset has no value, there is no need to provide protection for it. A primary goal of risk analysis is to ensure that only cost-effective safeguards are deployed. It makes no sense to spend $100,000 protecting an asset that is worth only $1,000. Therefore, the value of an asset directly affects and guides the level of safeguards and security deployed to protect it. As a rule, the annual costs of safeguards should not exceed the potential annual cost of asset value loss.

       Purchase cost

       Development cost

       Administrative or management cost

       Maintenance or upkeep cost

       Cost in acquiring asset

       Cost to protect or sustain asset

       Value to owners and users

       Value to competitors

       Intellectual property or equity value

       Market valuation (sustainable price)

       Replacement cost

       Productivity enhancement or degradation

       Operational costs of asset presence and loss

       Liability of asset loss

       Usefulness

       Relationship to research and development

      Assigning or determining the value of assets to an organization can fulfill numerous requirements by

       Serving as the foundation for performing a cost/benefit analysis of asset protection when performing safeguard selection

       Serving as a means for evaluating the cost-effectiveness of safeguards and countermeasures

       Providing values for insurance purposes and establishing an overall net worth or net value for the organization

       Helping senior management understand exactly what is at risk within the organization

       Preventing negligence of due care/due diligence and encouraging compliance with legal requirements, industry regulations, and internal security policies

      If a threat-based or threat-initiated risk analysis is being performed, then after the organization inventories threats and identifies vulnerable assets to those threats, asset valuation takes place.

      Identify Threats and Vulnerabilities

      For an expansive and formal list of threat examples, concepts, and categories, consult National Institute of Standards and Technology (NIST) Special Publication (SP) 800-30r1 Appendix D, “Threat sources,” and Appendix E, “Threat events.” For coverage of threat modeling, see Chapter 1.

      In most cases, a team rather than a single individual should perform risk assessment and analysis. Also, the team members should be from various departments within the organization. It is not usually a requirement that all team members be security professionals or even network/system administrators. The diversity of the team based on the demographics of the organization will help exhaustively identify and address all possible threats and risks.

      The Consultant Cavalry

      Risk assessment is a highly involved, detailed, complex, and lengthy process. Often risk analysis cannot be properly handled by existing employees because of the size, scope, or liability of the risk; thus, many organizations bring in risk management consultants to perform this work. This provides a high level of expertise, does not bog down employees, and can be a more reliable measurement of real-world risk. But even risk management consultants do not perform risk assessment and analysis on paper only; they typically employ risk assessment software. This software streamlines the overall task, provides more reliable results, and produces standardized reports that are acceptable to insurance companies, boards of directors, and so on.

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