The Official (ISC)2 CISSP CBK Reference. Aaron Kraus
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rather than enforce a desired behavior. The compensating control may not fully mitigate the risk, but it provides some level of security that wouldn't exist without any control being implemented. PCI-DSS provides some good examples of compensating controls usage.
Control Assessments
Periodic assessment of your security controls is equally as important as the selection and implementation of those controls. In many cases, your organization may have legal or regulatory requirements that dictate how and when to conduct security control assessments (SCA), but in all cases, you should routinely conduct control assessments to ensure that your security and privacy controls remain effective.
SCAs may take the form of self-assessments or external assessments conducted by third parties. There are many different SCA methodologies, but they generally include some form of the following assessment methods: examine, interview, and test. NIST 800-53A, “Assessing Security and Privacy Controls in Federal Information Systems and Organizations,” lays out some helpful guidelines for conducting controls assessments and describes the three assessment methods as follows:
Examine: This method is “the process of reviewing, inspecting, observing, studying, or analyzing one or more assessment objects (i.e., specifications, mechanisms, or activities). The purpose of the examine method is to facilitate assessor understanding, achieve clarification, or obtain evidence.” Assessors often begin an SCA by requesting a list of artifacts or evidence (such as security policies, configuration files, etc.) that they can examine to form an initial perspective.
Interview: This method is “the process of holding discussions with individuals or groups of individuals within an organization to once again, facilitate assessor understanding, achieve clarification, or obtain evidence.” After reviewing any evidence provided during the examine phase, assessors meet with key stakeholders to gain additional clarity on what security controls are in place and how they work.
Test: This method is “the process of exercising one or more assessment objects (i.e., activities or mechanisms) under specified conditions to compare actual with expected behavior.” In this stage, an auditor or assessor is seeking to confirm that security controls are implemented as they are documented and that they are operating effectively and as intended.
Chapter 6 covers security assessment extensively.
Monitoring and Measurement
Monitoring and measurement of your controls is an important part of operating a risk-based security program. In addition to conducting periodic (e.g., annual or quarterly) security and privacy control assessments, you should actively and intentionally monitor your controls to measure their effectiveness and assess the health of your overall security program. Depending on your organization's needs, you should develop a set of key performance indicators (KPIs) that allow you to quantify and measure the long-term performance of your controls.
Reporting
Conducting SCAs and other monitoring and measurement activities is useless without a well-managed reporting function. Auditors and assessors generally create formal reports that detail their findings for each control that is assessed. In addition, your security team should have a process to document and report any important discoveries or metrics to senior leadership, regulators, and other stakeholders.
Some laws, regulations, and industry requirements come with specific reporting guidelines; as an information security leader, you must be familiar with any such requirements that are relevant to your organization. In general, a well-managed risk-based security program includes some level of reporting for the following:
Internal audits (e.g., self-assessments)
External audits (i.e., regulator or any other third-party audits)
Significant changes to the organization's risk posture
Significant changes to security or privacy controls
Suspected or confirmed security breaches (or other incidents)
Continuous Improvement
A common goal among security leaders is to continuously improve their organization's security posture and measure their journey toward their desired end state. As a CISSP, you need to continuously identify whether your organization is improving its management of information security risks. You should also seek to continuously improve the return on investment (ROI) associated with the security tools, controls, and processes that your organization implements. There is a fine line between “not secure enough” and “perhaps too many security tools and processes.” As a CISSP, you should seek to continuously improve the efficiency of your organization's security management program.
Risk maturity modeling is a process that allows an organization to assess the strength of its security program and create a plan for continuous improvement based on their results. By identifying the maturity of its program on a predefined scale, an organization may better focus on what types of behaviors are necessary to improve, rather than getting caught up strictly in individual security gaps. Maturity models are discussed further in Chapter 8.
Risk Frameworks
A risk framework is a structured process for identifying, assessing, and managing an organization's risks. A number of frameworks have been developed to identify and evaluate risk. These frameworks have evolved to address the unique needs of different industries and regulations. Individually, these frameworks address assessment, control, monitoring, and audit of information systems in different ways, but all strive to provide internal controls to bring risk to an acceptable level. While there are several internationally accepted risk frameworks, a number of industry-specific frameworks have also been developed to meet specific needs.
Regardless of the framework, to effectively address risk in an organization, standard processes to evaluate the risks of operation of information systems must take into account the changing threat environment, the potential and actual vulnerabilities of systems, the likelihood that the risk will occur, and the impact to the organization should that risk become realized.
From a governance perspective, the selection of a framework should create a controls environment that is as follows:
Consistent: A governance program must be consistent in how information security and privacy are approached and applied.
Measurable: The governance program must provide a way to determine progress and set goals. Most control frameworks contain an assessment standard or procedure to determine compliance and, in some cases, risk as well.
Standardized: As with measurable, a controls framework should rely on standardization so results from one organization or part of an organization can be compared in a meaningful way to results from another organization.
Comprehensive: The selected framework should cover the minimum legal and regulatory requirements of an organization and be extensible to accommodate additional organization-specific requirements.
Modular: A modular framework is more likely to withstand the changes of an organization, as only the controls or requirements needing modification are reviewed and updated.
There are dozens of different risk management frameworks. While many of the frameworks address specific industry or organizational requirements, you should be aware of the broad characteristics of the more common frameworks.
International Standards Organization
The International Standards Organization has developed the ISO 31000 series of standards to identify principles for general risk management and to