Managing Information Security Risks: The OCTAVE (SM) Approach [Hardcover]

Many people seem to be looking for a silver bullet when it comes to information security. They often hope that buying the latest tool or piece of technology will solve their problems. Few organizations stop to evaluate what they are actually trying to protect (and why) from an organizational perspective before selecting solutions. In our work in the field of information security, we have found that security issues tend to be complex and are rarely solved simply by applying a piece of technology. Most security issues are firmly rooted in one or more organizational and business issues. Before implementing security solutions, you should consider characterizing the true nature of the underlying problems by evaluating your security needs and risks in the context of your business.

Considering the varieties and limitations of current security evaluation methods, it is easy to become confused when trying to select an appropriate method for evaluating your information security risks. Most of the current methods are "bottom-up": they start with the computing infrastructure and focus on the technological vulnerabilities without considering the risks to the organization's mission and business objectives. A better alternative is to look at the organization itself and identify what needs to be protected, determine why it is at risk, and develop solutions requiring both technology- and practice-based solutions.

A comprehensive information security risk evaluation approach

• Incorporates assets, threats, and vulnerabilities
• Enables decision makers to develop relative priorities based on what is important to the organization
• Incorporates organizational issues related to how people use the computing infrastructure to meet the business objectives of the organization
• Incorporates technological issues related to the configuration of the computing infrastructure
• Should be a flexible method that can be uniquely tailored to each organization

One way to create a context-sensitive evaluation approach is to define a basic set of requirements for the evaluation and then develop a series, or family, of methods that meet those requirements. Each method within the approach could be targeted to a unique operational environment or situation. We conceived the Operationally Critical Threat, Asset, and Vulnerability EvaluationSM (OCTAVESM) project to define a systematic, organizationwide approach to evaluating information security risks comprising multiple methods consistent with the approach. We also designed the approach to be self-directed, enabling people to learn about security issues and improve their organization's security posture without unnecessary reliance on outside experts and vendors.

An evaluation by itself only provides a direction for an organization's information security activities. Meaningful improvement will not occur unless the organization follows through by implementing the results of the evaluation and managing its information security risks. OCTAVE is an important first step in approaching information security risk management.

Before we developed OCTAVE, we performed expert-led Information Security Evaluations (ISEs) for organizations. A team of security experts would visit a site, interview selected information technology personnel and users of key systems, and examine selected pieces of the computing infrastructure for technological weaknesses. The assessors used their expertise to create a list of organizational and technological weaknesses (vulnerabilities). When the managers at a site received the list of vulnerabilities and corresponding recommendations, they often did not know how to begin to overcome the weaknesses. Which issues should they address first, the organizational or the technological? With limits on the funds and staff available, what are the top five priorities? These are good questions. Unfortunately, when you examine only vulnerabilities, it is hard to establish appropriate guidelines. You need to look at the vulnerabilities in the context of what the organization is trying to achieve before you can start establishing priorities.

In addition to our experience with vulnerability evaluations, we had also developed and applied a variety of software development risk evaluation and management techniques Williams 00 and Dorofee 96. These techniques focused on the critical risks that could affect project objectives.

With these experiences, we decided to focus on a risk-based approach rather than a vulnerability-based approach. A risk-based approach could help people understand how information security affects their organization's missions and business objectives, establishing which assets are important to the organization and how they are at risk. Vulnerability evaluations could then be performed in the context of this risk information. Because information security risks are tied to an organization's missions and business objectives, it became necessary to include business staff in addition to information technology personnel in the evaluation.

A second important observation from our vulnerability evaluation days concerned a given site's level of involvement and subsequent ownership of the results. Because the vulnerability evaluations were highly dependent on the expertise of the assessors, site personnel involved in the process participated very little. When we were able to go back to a site, we saw the same vulnerabilities from one visit to the next. There had been little or no organizational learning. People in those organizations did not feel "ownership" of the various evaluations' results and had therefore not implemented the findings. We decided that sites needed to be more involved in security evaluations in order to learn about their security processes and participate in developing improvement recommendations. We started to develop a self-directed evaluation approach that

• Focused on risks to information assets
• Focused on practice-based mitigation using recognized, good security practices1
• Included business personnel as well as staff from the information technology department
• Involved a site's personnel in all aspects of the evaluation

In June 1999 we published a report describing the OCTAVE framework Alberts 99, a specification for an information security risk evaluation. This was refined into the OCTAVE Method Alberts 01a, which was developed for large-scale organizations. In addition, we are developing a second method targeted at small organizations. During these efforts, we determined that the OCTAVE framework did not sufficiently capture the general approach to, or requirements for, the self-directed information security risk evaluations that we wanted. We refined the framework into the OCTAVE criteria Alberts 01b, namely, a set of principles, attributes, and outputs that define the OCTAVE approach.

This book focuses on four key aspects of information security risk evaluation.

• It defines an approach for self-directed information security risk evaluations (OCTAVE criteria).
• It illustrates how the evaluation approach can be implemented in an organization using the OCTAVE Method.
• It shows how the OCTAVE Method can be tailored to different types of organizations.
• It describes how this approach provides a foundation for managing information security risks.

To address these key issues, we have divided the contents of the book into three parts.

• Part I, the Introduction, summarizes the OCTAVE approach and presents the principles, attributes, and outputs of self-directed information security risk evaluations.
• Part II, The OCTAVE Method, illustrates one way in which the OCTAVE approach can be implemented in an organization. This part begins with an "executive summary" of the OCTAVE Method and then presents the method in detail.
• Part III, Variations on the OCTAVE Approach, describes ideas for tailoring the OCTAVE Method for different types of organizations. This part also presents basic concepts related to managing information security risks after the evaluation.

Three appendices supplement the material provided in the main text.

• Appendix A presents a sample final report from an OCTAVE example scenario.
• Appendix B shows OCTAVE Method worksheets and instructions.
• Appendix C lists a catalog of practices (a structured collection of commonly used good security practices).

This book is written for a varied audience. Some familiarity with security issues is helpful, but not essential; we define all concepts and terms as they appear. The book should satisfy people who are new to security as well as experts in security and risk management.

Information security risk evaluations are appropriate for anyone who uses networked computers to conduct business and thus may have critical information assets at risk. This book is for people who need to perform information security risk evaluations and who are interested in using a self-directed method that addresses both organizational and information technology issues. Managers, staff members, and information technology personnel concerned about and responsible for protecting critical information assets should all find this book useful.

In addition, consultants who provide information security services to other organizations may be interested in seeing how the OCTAVE approach or the OCTAVE Method might be incorporated into their existing products and services. Consumers of information security risk evaluation products and services can use the principles, attributes, and outputs of the OCTAVE approach to understand what constitutes a comprehensive approach for evaluating information security risks. Consumers can also use the principles, attributes, and outputs as a benchmark for selecting products and services that are provided by vendors and consultants.

The OCTAVE Method requires an interdisciplinary analysis team to perform the evaluation and act as a focal point for security improvement efforts. The primary audience for this book, then, is anyone who might be on the analysis team or work with them. The book includes "how to" information for conducting an evaluation as well as concepts related to managing risks after the evaluation. For an analysis team, the entire book is applicable.

Those who want to understand the OCTAVE approach should read Part I. Those who just want an overview of the OCTAVE Method and a general idea of how it might be used should read Chapters 1 and 3. People who already perform information security risk evaluations and are looking for additional ideas for improvement should first read Chapters 1 and 3 and then decide which areas to explore further. Those ready to start learning how to conduct self-directed information security evaluations in their organizations should read Part II. Finally, people who are interested in customizing the OCTAVE Method or learning about what to do after an evaluation should read Part III.OCTAVE was developed at the CERT Coordination Center (CERT/CC). Established in 1988, it is the oldest computer security response group in existence. The center both advises Internet sites that have had their security compromised and offers tools and techniques that enable typical users and administrators to protect systems effectively from damage caused by intruders. The CERT/CC’s home is the Software Engineering Institute (SEI), a federally funded research and development center operated by Carnegie Mellon University, with a broad charter to improve the practice of software engineering.

1. Practices in the catalog of practices (Appendix C) were derived from several sources of security practices including CERT/CC, the British Standards Institute, the National Institute for Standards and Technology, and government regulations.