Electronic Bulletin Number 63 - September, 2009

 
 
Security risk management
 
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Summary

This contribution provides  a high-level description of the process by which risk management can be carried out. Two models are overviewed: “Risk Management Guide for Information Technology - NIST SP 800-30”, and ISO/IEC 27005:2008, Information technology - Security techniques -Information security risk management.

1. Introduction

The explosive growth in the use of the information and communication technologies (ICT) infrastructure has increased the reliance of organizations and individuals on the protection of the information transmitted and stored over telecommunications networks.

This has led to a heightened awareness of the need to protect the

  • Confidentiality of information by ensuring that information is accessible only to those authorized to have access;

  • Integrity of the information by safeguarding the accuracy and completeness of information and processing methods; and

  • Availability of information by ensuring that authorized users have access to information and associated assets when required.

To meet these security objectives, organizations practice safe security techniques based on specialized methodologies to manage potential risks.

Security risk management plays a critical role in protecting an organization’s information from security risk and it is defined as the logical and analytical process of identifying risk, assessing risk, and taking steps to reduce risk to an acceptable level. Security risks are managed by:

  • Analyzing and assessing threats and risks to which sensitive information and assets are exposed;

  • Selecting risk-mitigation safeguards; and

  • Developing and testing contingency and business resumption plans.

Managing security risks means defining what is at risk, the magnitude (impact) of harm caused by a threat, the causes or events with the potential to cause harm to an ICT infrastructure, and what to do about the risk. A threat and risk assessment is one means to manage risk. Other means of managing risk would be education and awareness, security policies, operational standards, and technical documentations.

The following section provides a description of risk management approaches in general as well as applications to manage potential security’s risks.

2. Risk Management Overview

A number of Risk Management Frameworks are available in the open literature. Although these frameworks, and processes defined within them, differ in detail, there is considerable overlap in the material covered.

The following themes recur [1], [2], [3], [4], [5], [6], [7]:

a) Identification of critical assets

As it is not cost-effective to protect all assets, it is essential that the critical assets be identified so that particular care may be taken to protect them. The designation should be made from the business context, through consideration of the impact of the loss or degradation of an asset on the business as a whole.

b) Identification of risks

A disciplined, comprehensive identification of risks should be undertaken. It should include environmental risks, as well as those caused by humans. The “accidental insider” group includes human error as well as accidental misconfiguration conducted by inadequately trained personnel. When people are the threat, the analysis should include who they are, their motivation for threatening the system, and the means by which they would attempt to achieve their goals.

c) Impact Assessment

It is necessary to relate each risk to one or more of the architectural components and determine the potential impact of the threat on the asset..

d) Treatments

This activity involves planning and implementing the best course of action: accepting the risk as it exists today; actively managing the risk; watching for changes in risk characteristics (and modifying the plan as needed); and investigating more about the risk until enough is known that one of the others planning options becomes appropriate.

e) Reporting

Who needs to know about the risks? Who needs to know about incidents? Who needs to know about threats that succeed?

f) Information Sharing

What information should be shared? How should the sharing occur? What are the restrictions on sharing (e.g., should the data be anonymized before sharing?)

g) Monitoring/Audit

Is there a need for internal audits? Is there a need for third-party (external) auditors? Do the regulators require audits? Do the shareholders require audits?

h) Regulatory/Legislative

What is the regulatory environment? What laws need to be followed? What security requirements are imposed by external bodies?

3. Security Risk Management Process

Information security risk analysis/risk management methods usually support the general concepts specified in ISO/IEC 27000 standards [4] and are designed to assist all types of organizations in the satisfactory implementation of information security based on a risk management approach. The following sub-sections describe a risk management process followed for an overview of security risk management guidelines.

3.1. Risk Management Guide for Information Technology - NIST SP 800-30

The NIST approach [5] involves a three-step process: risk assessment; risk mitigation; and evaluation and assessment.

Risk assessment

This process allows determining the level of the potential threat and their risks associated with an ICT system. The risk assessment process includes:

  • System characterization: establishes the scope of the risk assessment effort and provides information essential to defining the risk.

  • Threat identification: identifies the potential threat-sources that could exploit system vulnerabilities:

i. Human: unintentional acts (e.g., inadvertent data entry), or deliberate actions (e.g., network based attacks, malicious software upload, or unauthorized access);

ii. Natural: floods, earthquakes, electrical storms; and

iii. Environmental (e.g., long-term power failure).

  • Vulnerability identification: identifies the system vulnerabilities (flaws or weaknesses) that could be exercised by the potential threat-sources.

  • Control analysis: specifies the controls used for the information system to mitigate the probability of a vulnerability and reduce its impact. Examples of effective security or risk reduction controls are:

i. technical controls incorporated into computer hardware, software, or firmware, and nontechnical controls such as security policies; operational procedures; and personnel and environmental security;

ii. preventive controls, e.g., access control enforcement, encryption, and authentication; and

iii. security requirements checklist to be used to validate security compliance/noncompliance.

  • Probability determination: determines the probability (High, Medium, or Low) that a potential vulnerability may be exercised. There are three factors to be considered:

i. threat-source motivation and capability;

ii. nature of the vulnerability; and

iii. existence and effectiveness of current controls.

  • Impact analysis: prioritizes the impact levels associated with the compromise of an organization’s information assets based on a qualitative or quantitative assessment of the criticality of those assets. In this step it is necessary to relate each risk to the architectural components and determine the potential impact of the threat on the asset, and subsequently, establish the magnitude of the impact (High, Medium, or Low) resulting from a successful threat.

  • Risk determination: measures the level of risk to the information system. It is expressed as a function of the

i. probability of a threat-source;

ii. magnitude of the impact; and

iii. capability of security controls for reducing or eliminating a risk.

  • Control recommendations: provides input to the risk mitigation process and are the results of the risk assessment process. The goal of this step is to reduce - to an acceptable level - the level of risk to the information system and its data. A cost-benefit analysis should be conducted to demonstrate that the costs of implementing the recommended controls can be justified by the reduction in the level of risk.

  • Results documentation: describes the threats and vulnerabilities, risk measurements, and recommendations for control implementation by documenting them in an official report. Its purpose is to help in the process of making decisions on policy, procedural, budget, and system changes to reduce and correct potential losses.

Risk mitigation

Risk mitigation is a systematic methodology to reduce risk. It involves prioritizing, evaluating, and implementing the appropriate risk-reducing controls recommended from the risk assessment process. The implementation of the best course of action may vary depending on the organization.

There are four risk mitigation options:

1. Risk retention: to accept the potential risk and continue operating, or to implement controls to lower the risk to an acceptable level

2. Risk avoidance: to avoid the risk by eliminating the risk cause and/or consequence

3. Risk reduction: to limit the risk by implementing controls that minimize the adverse impact of a threat exercising a vulnerability

4. Risk transference: to transfer the risk by using other options to compensate for the loss, such as purchasing insurance.

After identifying the possible controls and evaluating their viability and effectiveness, a cost-benefit analysis to determine which controls are appropriate to allocate resources is conducted. Its purpose is to demonstrate that the costs of implementing the controls can be justified by the reduction in the level of risk.

The cost-benefit analysis encompasses:

  • Impact of implementing the controls (new or enhanced);

  • Impact of not implementing the controls (new or enhanced);

  • Costs of the implementation: hardware and software, policies and procedures, personnel and training, and maintenance;

  • Costs and benefits against system and data criticality.

Once the cost of implementation has been established and by comparing their results, it can be decided whether or not to implement the risk control measures.

Evaluation and Assessment

The network (components and software applications), personnel and security policies are likely to change over time. These changes mean that new risks will rise and risks previously mitigated may again become a concern. Thus, the risk management process continues with the identification of new or re-emerging risks for as long as the infrastructure activity or business process is ongoing.

In evaluating this process the following actions are available:

  • Continue the current plan option - when data indicates the risk is under control;

  • Invoke contingency - when the original plan did not work as expected;

  • Re-plan - go back to the planning step and change course; or

  • Close the risk - when the risk's probability and/or potential impact is zero or very low.

The next section describes a security risk management guideline based on the ISO/IEC 27005 standard which intends to provide fundamental contributions to the well being and security of any organization.

3.2. Security Risk Management Guideline

The Security Risk Management guideline described below is based on the ISO/IEC 27005 standard [4] which intends to provide fundamental contributions to the well being and security of any organization. This guideline creates an ongoing process that drives the organization towards to effective controls to mitigate security risks. The follow general practice references many industry accepted standards for managing security risk and incorporates the first three phases of the risk management process described before.

First phase: Risk Assessment

Steps in this phase include planning, data gathering, and risk prioritization. Risk prioritization involves qualitative and quantitative approaches to provide reliable risk information within reasonable trade-offs of time and effort.

Second phase: Risk Treatment Options

During this phase it is determining how to address the key risks in the most effective and cost efficient manners. The control solutions to be implemented are defined after an evaluation of all the recommended controls, estimated costs, and degrees of risk reduction are measured. The output of this phase is a clear and actionable plan to control or accept each of the top risks identified in the Assessing Risk phase.

Third phase: Treatment Evaluation

During this phase it is created and executed plans based on the control solutions that emerged during the decision support process to measure the effectiveness of the program. When the previous phases of the security risk management process are complete, organizations estimate their progress with regard to security risk management as a whole.

The follow flowcharts (from ISO/IEC 27005) provide a brief of the information Security Risk Management phases described above.

 

Figure 1. Risk Management Process (ISO/IEC 27005)

Finally, the most important keys for implementing a successful security risk management program will build on:

  • Management’s commitment and full support and participation of the ICT teams;

  • The expertise to apply the security risk assessment methodology to a specific site and system, identify mission risks, and provide cost-effective protection;

  • The awareness and cooperation of members of the user community; and

  • An ongoing evaluation of the ICT-related mission risks.

4. Summary

This contribution provides Security Risk Management input to the Technical Notebook on Cyber security. It provides a high-level description of the process by which risk management can be carried out. Two models are overviewed: “Risk Management Guide for Information Technology - NIST SP 800-30”, and ISO/IEC 27005:2008, Information technology - Security techniques -Information security risk management.

It is recommended that the Cyber security Rapporteur of the Working Group on Policy and Regulatory Matters to consider incorporating this contribution in Chapter 3 of the Technical Notebook of Cyber Security.

 

Oscar Avellaneda & Magdoly Rondon
Industry Canada

 

 

Additional Information: This document was published as document: CCP.I-TEL/doc. 1733/09.

References

1. A Risk Management Standard, IRM - The Institute of Risk Management, http://www.theirm.org/publications/documents/Risk_Management_Standard_030820.pdf

2. Cyber security Risk Management: an economics perspective, Dr. Lawrence Gordon, http://www.rhsmith.umd.edu/faculty/lgordon/cybersecurity/CYBERSECURITY%20RISK%
20MANAGEMENT.AN%20ECONOMICS%20PERSPECTIVE.ppt

3. CSE, “A Guide to Security Risk Management for Information Technology Systems”, Communications Security Establishment MG-2, January 1996.

4. ISO/IEC 27005: Information security risk management (RISK ASSESSMENT REQUIREMENTS and MANAGEMENT)

5. Risk Management Guide for Information Technology Systems, NIST, Special Publication 800-30 http://csrc.nist.gov/publications/nistpubs/800-30/sp800-30.pdf

6. “Risk Management Framework”, Cigital Inc., sponsored by DHS National Cyber Security Division, 2005, https://buildsecurityin.us-cert.gov/daisy/bsi/articles/best-practices/risk/250-BSI.html

7. Risk Management Framework (RMF) OVERVIEW, http://csrc.nist.gov/groups/SMA/fisma/framework.html

 

 
 

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