NIST SP 800-39FPD Chapter 3
APPLYING RISK MANAGEMENT CONCEPTS ACROSS AN ORGANIZATION
This chapter describes a life cycle-based process for managing information security risk including: (i) an overview of the risk management process; (ii) how organizations establish the context for risk-based decisions; (iii) how organizations assess risk considering threats, vulnerabilities, likelihood, and consequences/impact; (iv) how organizations respond to risk once determined; and (v) how organizations monitor risk over time with changing mission/business needs, operating environments, and supporting information systems . The risk management process, introduced in Chapter Two, is described in this chapter along with its applicability across the three tiers of risk management. Each of the steps in the risk management process (i.e., risk framing, risk assessment, risk response, and risk monitoring) is described in a structured manner focusing on the inputs or preconditions necessary to initiate the step, the specific activities that compose the step, and the outputs or post conditions resulting from the step. The effect of the risk concepts described in Chapter Two (e.g., risk tolerance, trust, and culture) are also discussed in the context of the risk management process and its multitiered application. Figure 4 illustrates the risk management process as applied across the tiers--organization, mission/business process, and information systems.
The steps in the risk management process are not inherently sequential in nature. The steps are performed in different ways, depending on the particular tier where the step is applied and on prior activities related to each of the steps. What is consistent is that the outputs or post conditions from a particular risk management step directly impact one or more of the other risk management steps in the risk management process. Organizations have significant flexibility in how the risk management steps are performed (i.e., sequence, degree of rigor, formality, and thoroughness of application) and in how the results of each step are captured and shared--both internally and externally. Ultimately, the objective of applying the risk management process and associated risk-related concepts is to develop a better understanding of information security risk in the context of the broader actions and decisions of organizations and in particular, with respect to organizational operations and assets, individuals, other organizations, and Nation.
3.1 FRAMING RISK
Risk framing establishes the context and provides a common perspective on how organizations manage risk. Risk framing, as its principal output, produces a risk management strategy that addresses how organizations intend to assess risk, respond to risk, and monitor risk. The risk management strategy makes explicit the specific assumptions, constraints, risk tolerances, and priorities/trade-offs used within organizations for making investment and operational decisions. The risk management strategy also includes any strategic-level decisions and considerations on how risk to organizational operations and assets, individuals, other organizations, and the Nation, is to be managed by senior leaders/executives.
At Tier 1, senior leaders/executives, in consultation and collaboration with the risk executive (function), define the organizational risk frame including the types of risk decisions (e.g., risk responses) supported, how and under what conditions risk is assessed to support those risk decisions, and how risk is monitored (i.e., to what level of detail, in what form, and with what frequency). At Tier 2, mission/business owners apply their understanding of the organizational risk frame to address concerns specific to the organization's missions/business functions (e.g., additional assumptions, constraints, priorities, and trade-offs). At Tier 3, program managers, information system owners, and common control providers apply their understanding of the organizational risk frame based on how decision makers at Tiers 1 and 2 choose to manage risk.
The Risk Management Framework is the primary means for addressing risk at Tier 3. The RMF addresses concerns specific to the design, development, implementation, operation, and disposal of organizational information systems and the environments in which those systems operate. The risk frame can be adapted at Tier 3 based on the current phase of the SDLC, which further constrains potential risk responses. Initially, organizational risk frames might not be explicit or might not be defined in terms that correspond to the risk management tiers. In the absence of explicit risk frames (describing assumptions, constraints, risk tolerance, and priorities/trade-offs), mission/business owners can have divergent perspectives on risk or how to manage it. This impedes a common understanding at Tier 1 of how information security risk contributes to organizational risk, and at Tier 2, of how risk accepted for one mission or business function potentially affects risk with respect to other missions/business functions. Differences in risk tolerance and the underlying assumptions, constraints, and priorities/trade-offs are grounded in operational and/or architectural considerations and should be understood and accepted by senior leaders/executives within their respective organizations.
STEP 1: RISK FRAMING
Inputs and Preconditions
Risk framing is the set of assumptions, constraints, risk tolerances, and priorities/trade-offs that shape an organization's approach for managing risk. Risk framing is informed by the organizational governance structure, financial posture, legal/regulatory environment, investment strategy, culture, and trust relationships established within and among organizations. Inputs to the risk framing step include, for example, laws, policies, directives, regulations, contractual relationships, and financial limitations which impose constraints on potential risk decisions by organizations. Other inputs to risk framing can include, for example, specific information from organizations to make explicit: (i) the identification of trust relationships and trust models (see Appendix G) that derive from existing memoranda of understanding or agreement (MOUs or MOAs); and (ii) the identification of the governance structures and processes that indicate the extent of or limits on decision-making authority for risk decisions that can be delegated to mission or business owners. The key precondition for risk framing is senior leadership commitment to defining an explicit risk management strategy and holding mission/business owners responsible and accountable for implementing the strategy.
The guidance produced by the risk framing step, and the underlying assumptions, constraints, trade-offs, and priorities used to develop that guidance, may be inappropriate to one or more organizational missions or business functions. In addition, the risk environment has the potential to change over time. Thus, the risk management process allows for feedback to the risk framing step from the other steps in the process, as follows:
- Risk assessment: Information generated during the risk assessment may influence the original assumptions, change the constraints regarding appropriate risk responses, identify additional tradeoffs, or shift priorities. For example, the characterization of adversaries and representative tactics, techniques, and procedures (TTP), and/or organizational sources of vulnerability information may not be consistent with how some organizations conduct their missions/business functions; a source of threat/vulnerability information that is useful for one mission/business function could, in fact, be useful for others; or organizational guidance on assessing risk under uncertainty may be too onerous, or insufficiently defined, to be useful for one or more mission/business functions.
- Risk response: Information uncovered during the development of alternative courses of action could reveal that risk framing has removed or failed to uncover some potentially high-payoff alternatives from consideration. This situation may challenge organizations to revisit original assumptions or investigate ways to change established constraints.
- Risk monitoring: Security control monitoring by organizations could indicate that a class of controls, or a specific implementation of a control, is relatively ineffective, given investments in people, processes, or technology. This situation could lead to changes in assumptions about which types of risk responses are preferred by organizations. Monitoring of the operational environment could reveal changes in the threat landscape (e.g., changes in the tactics, techniques, and procedures observed across all organizational information systems; increasing frequency and/or intensity of attacks against specific missions/business functions) that cause organizations to revisit original threat assumptions and/or to seek different sources of threat information. Significant advances in defensive or proactive operational and technical solutions could generate the need to revisit the investment strategy identified during the framing step. Monitoring of legal/regulatory environments could also influence changes in assumptions or constraints. Also, monitoring of risk being incurred might result in the need to reconsider the organizational risk tolerance if the existing statement of risk tolerance does not appear to match the operational realities.
TASK 1-1: Identify assumptions about threats, vulnerabilities, consequences/impact, and likelihood of occurrence that affect how risk is assessed, responded to, and monitored within the organization.
Supplemental Guidance: Organizations that identify, characterize, and provide representative examples of threat sources, vulnerabilities, consequences/impacts, and likelihood determinations promote a common terminology and frame of reference for comparing and addressing risks across disparate mission/business areas. Organizations can also select appropriate risk assessment methodologies, depending on organizational governance, culture, and how divergent the missions/business functions are within the respective organizations. For example, organizations with highly centralized governance structures might elect to use a single risk assessment methodology. Organizations with hybrid governance structures might select multiple risk assessment methodologies for Tier 2, and an additional risk assessment methodology for Tier 1 that assimilates and harmonizes the findings, results, and observations of the Tier 2 risk assessments. Alternatively, when autonomy and diversity are central to the organizational culture, organizations could define requirements for the degree of rigor and the form of results, leaving the choice of specific risk assessment methodologies to mission/business owners.
Threat sources cause events having undesirable consequences or adverse impacts on organizational operations and assets, individuals, other organizations, and the Nation. Threat sources include: (i) hostile cyber/physical attacks; (ii) human errors of omission or commission; or (iii) natural and man-made disasters. For threats due to hostile cyber attacks or physical attacks, organizations provide a succinct characterization of the types of tactics, techniques, and procedures employed by adversaries that are to be addressed by safeguards and countermeasures (i.e., security controls) deployed at Tier 1 (organization level), at Tier 2 (mission/business process level), and at Tier 3 (information system level)--making explicit the types of threat-sources that are to be addressed as well as making explicit those not being addressed by the safeguards/countermeasures. Adversaries can be characterized in terms of threat levels (based on capabilities, intentions, and targeting) or with additional detail. Organizations make explicit any assumptions about threat source targeting, intentions, and capabilities. Next, organizations identify a set of representative threat events. This set of threat events provides guidance on the level of detail with which the events are described. Organizations also identify conditions for when to consider threat events in risk assessments. For example, organizations can restrict risk assessments to those threat events that have actually been observed (either internally or externally by partners or peer organizations) or alternatively, specify that threat events described by credible researchers can also be considered. Finally, organizations identify the sources of threat information found to be credible and useful (e.g., sector Information Sharing and Analysis Centers [ISACs]). Trust relationships determine from which partners, suppliers, and customers, threat information is obtained as well as the expectations placed on those partners, suppliers and customers in subsequent risk management process steps. By establishing common starting points for identifying threat sources at Tier 1, organizations provide a basis for aggregating and consolidating the results of risk assessments at Tier 2 (including risk assessments conducted for coalitions of missions and business areas or for common control providers) into an overall assessment of risk to the organization as a whole. At Tier 2, mission/business owners may identify additional sources of threat information specific to organizational missions or business functions. These sources are typically based on: (i) a particular business or critical infrastructure sector (e.g., sector ISAC); (ii) operating environments specific to the missions or lines of business (e.g., maritime, airspace); and (iii) external dependencies (e.g., GPS or satellite communications). The characterization of threat sources are refined for the missions/business functions established by organizations--with the results being that some threat sources might not be of concern, while others could be described in greater detail. At Tier 3, program managers, information system owners, and common control providers consider the phase in the SDLC to determine the level of detail with which threats can be considered. Greater threat specificity tends to be available later in the SDLC.
Organizations identify approaches used to characterize vulnerabilities, consistent with the characterization of threat sources and events. Vulnerabilities can be associated with exploitable weakness or deficiencies in: (i) the hardware, software, or firmware components that compose organizational information systems (or the security controls employed within or inherited by those systems; (ii) mission/business processes, enterprise architectures, or information security architectures implemented by organizations; or (iii) organizational governance structures or processes. Vulnerabilities can also be associated with the susceptibility of organizations to adverse impacts, consequences, or harm from external sources (e.g., physical destruction of non-owned infrastructure such as electric power grids). Organizations provide guidance regarding how to consider dependencies on external organizations as vulnerabilities in the risk assessments conducted. The guidance can be informed by the types of trust relationships established by organizations with external providers. Organizations identify the degree of specificity with which vulnerabilities are described (e.g., general terms, Common Vulnerability Enumeration [CVE] identifiers, identification of weak/deficient security controls), giving some representative examples corresponding to representative threats. Organizational governance structures and processes determine how vulnerability information is shared across organizations. Organizations may also identify sources of vulnerability information found to be credible and useful. At Tier 2, mission/business owners may choose to identify additional sources of vulnerability information (e.g., a sector ISAC for information about vulnerabilities specific to that sector). At Tier 3, program managers, information system owners, and common control providers consider the phase in the SDLC--and in particular, the technologies included in the system - to determine the level of detail with which vulnerabilities can be considered. Organizations make explicit any assumptions about the degree of organizational or information system vulnerability to specific threat sources (by name or by type).
Consequences and Impact
Organizations provide guidance on how to assess impacts to organizational operations (i.e., mission, functions, image, and reputation), organizational assets, individuals, other organizations, and the Nation (e.g., using FIPS 199, CNSS Instruction 1253, or a more granular approach). Organizations can experience the consequences/impact of adverse events at the information system level (e.g., failing to perform as required), at the mission/business process level (e.g., failing to fully meet mission/business objectives), and at the organizational level (e.g., failing to comply with legal or regulatory requirements, damaging reputation or relationships, or undermining long-term viability). Organizations determine at Tier 1, which consequences and types of impact are to be considered at Tier 2, the mission/business process level. An adverse event can have multiple consequences and different types of impact, at different levels, and in different time frames. For example, the exposure of sensitive information (e.g., personally identifiable information) by a particular mission/business area (e.g., human resources) can have organization-wide consequences and adverse impact with regard to reputation damage; the information system consequence/impact for multiple systems of an attacker more easily overcoming identification and authentication security controls; and the mission/business process consequence/impact (for one or more mission/business areas) of an attacker falsifying information on which future decisions are based. To ensure consistency, organizations determine at Tier 1, how consequences/impacts experienced in different time frames are to be assessed. At Tier 2, mission/business owners may amplify organizational guidance, as appropriate. The types of consequences and impact considered in risk determinations are identified to provide a basis for determining, aggregating, and/or consolidating risk results and to facilitate risk communication. Organizations also provide guidance to Tier 2 and Tier 3 with regard to the extent that risk assessments are to consider the risk to other organizations and the Nation. Organization make explicit any assumptions about the degree of impact/consequences related to specific threat sources (by name or by type) or through specific vulnerabilities (individually or by type).
Organizations can employ a variety of approaches for determining the likelihood of threat events. Some organizations treat the likelihood that a threat event will occur and the likelihood that, if it occurs, it will result in adverse effects as separate factors, while other organizations assess threat likelihood as a combination of these factors. In addition, some organizations prefer quantitative risk assessments while other organizations, particularly when the assessment involves a high degree of uncertainty, prefer qualitative risk assessments. Likelihood determinations can be based on either threat assumptions or actual threat data (e.g., historical data on cyber attacks, historical data on earthquakes, or specific information on adversary capabilities, intentions, and targeting). When specific and credible threat data is available (e.g., types of cyber attacks, cyber attack trends, frequencies of attacks), organizations can use the empirical data and statistical analyses to determine more specific probabilities of threat events occurring. Organizations select a method consistent with organizational culture and risk tolerance. Organizations can also make explicit assumptions concerning the likelihood that a threat event will result in adverse effects as follows: (i) worst case (i.e., attack will be successful unless strong, objective reasons to presume otherwise); (ii) best case (i.e., attack will not be successful unless specific, credible information to the contrary); or (iii) something in between best and worst cases (i.e., the most probable case). Organizations document any overarching assumptions. Organizations can use empirical data and statistical analyses to help inform any of the approaches used to determine the likelihood of threat events occurring. Organizations select a method consistent with organizational culture, understanding of the operational environment, and risk tolerance.
TASK 1-2: Identify constraints on the conduct of risk assessment, risk response, and risk monitoring activities within the organization.
Supplemental Guidance: The execution of the risk management process can be constrained in various ways, some of which are direct and obvious, while others are indirect. Financial limitations can constrain the set of risk management activities directly (e.g., by limiting the total resources available for investments in risk assessments or in safeguards or countermeasures) or indirectly (e.g., by eliminating activities which, while involving relatively small investments in risk response, entail curtailing or discarding investments in legacy information systems or information technology). Organizations might also discover that legacy information systems may require large development investments to address items identified during risk assessments. Constraints can also include legal, regulatory, and/or contractual requirements. Such constraints can be reflected in (and indirectly take the form of), organizational policies (e.g., restrictions on outsourcing, restrictions on and/or requirements for information to be gathered as part of risk monitoring). Organizational culture can impose indirect constraints on governance changes (e.g., precluding a shift from decentralized to hybrid governance structures) and which security controls are considered by organizations as potential common controls. In particular, organizational attitudes toward information technology risk that, for example, favor extensive automation and early adoption of new technologies can constrain the degree of risk avoidance and perhaps risk mitigation that can be achieved. At Tier 2, mission/business owners interpret constraints in light of organizational missions/business functions. Some regulatory constraints may not apply to particular missions/business functions (e.g., regulations that apply to international operations, when mission/business areas are restricted to the United States). Alternately, additional requirements may apply (e.g., mission/business processes performed jointly with another organization, which imposes contractual constraints). At Tier 3, information system owners, common control providers, and/or program managers interpret the organization-wide and mission/business function-specific constraints with respect to their systems and environments of operation (e.g., requirements to provide specific security controls are satisfied through common controls).
TASK 1-3: Identify the level of risk tolerance for the organization.
Supplemental Guidance: Risk tolerance is the level of risk that organizations are willing to accept in pursuit of strategic goals and objectives. Organizations define information security-related risk tolerance organization-wide considering all missions/business functions. Organizations can use a variety of techniques for identifying information security risk tolerance (e.g., by establishing zones in a likelihood-impact trade space or by using a set of representative scenarios). Organizations also define tolerance for other types of organizational and operational risks (e.g., financial, risk, safety risk, compliance risk, or reputation risk). At Tier 2, mission/business owners may have different risk tolerances from the organization as a whole. The risk executive (function) provides organizations with ways to resolve such differences in risk tolerances at Tier 2. The level of residual risk accepted by authorizing officials for information systems or inherited common controls is within the organizational risk tolerance, and not the individual risk tolerances of those authorizing officials. In addition, organizations provide to Tier 2 and Tier 3, guidance on evaluating risk for specific mission/business processes or information systems and a focus on near-term mission/business effectiveness with the longer-term, strategic focus of the organizational risk tolerance. See Section 2.3.3 for additional information on risk tolerance.
PRIORITIES AND TRADE-OFFS
TASK 1-4: Identify priorities and trade-offs considered by the organization in managing risk.
Supplemental Guidance: Risk is experienced at different levels, in different forms, and in different time frames. At Tier 1, organizations make trade-offs among and establish priorities for responding to such risks. Organizations tend to have multiple priorities that at times conflict, which generates potential risk. Approaches employed by organizations for managing portfolios of risks reflect organizational culture, risk tolerance, as well as risk-related assumptions and constraints. These approaches are typically embodied in the strategic plans, policies, and roadmaps of organizations which may indicate preferences for different forms of risk response. For example, organizations may be willing to accept short-term risk of slightly degraded operations to achieve long-term reduction in information security risk. However, this trade-off could be unacceptable for one particularly critical mission/business function (e.g., real-time requirements in many industrial/process control systems). For that high-priority area, a different approach to improving security may be required including the application of compensating security controls.
Outputs and Post Conditions
The output of the risk framing step is the risk management strategy that identifies how organizations intend to assess, respond to, and monitor risk over time. The framing step also produces a set of organizational policies, procedures, standards, guidance, and resources covering the following topics: (i) scope of the organizational risk management process (e.g., organizational entities covered; mission/business functions affected; how risk management activities are applied within the risk management tiers); (ii) the characterization of threat sources, in particular threat agents; (iii) sources of threat information; (iv) representative threat events, in particular, adversary tactics, techniques, and procedures; (v) when to consider and how to evaluate threats; (vi) sources of vulnerability information; (vii) risk assessment methodologies to be used; (viii) risk assumptions; (ix) risk tolerances; (x) constraints on executing risk management activities; and (xi) organizational priorities and trade-offs. Outputs from the risk framing step serve as inputs to the risk assessment, risk response, and risk monitoring steps.
3.2 ASSESSING RISK
Risk assessment identifies, prioritizes, and estimates risk to organizational operations (i.e., mission, functions, image, and reputation), organizational assets, individuals, other organizations, and the Nation, resulting from the operation and use of information systems. Risk assessments use the results of threat and vulnerability assessments to identify and evaluate risk in terms of likelihood of occurrence and potential adverse impact (i.e., magnitude of harm) to organizations, assets, and individuals. Risk assessments can be conducted at any of the risk management tiers with different objectives and utility of the information produced. For example, risk assessments conducted at Tier 1 or Tier 2 focus on organizational operations, assets, and individuals--whether comprehensive across mission/business lines or only on those assessments that are cross-cutting to the particular mission/business line. Organization-wide assessments of risk can be based solely on the assumptions, constraints, risk tolerances, priorities, and trade-offs established in the risk framing step (derived primarily from Tier 1 activities) or can be based on risk assessments conducted across multiple mission/business lines (derived primarily from Tier 2 activities). Risk assessments conducted at one tier can be used to refine/enhance threat, vulnerability, likelihood, and impact information used in assessments conducted in other tiers. The degree that information from risk assessments can be reused is shaped by the similarity of missions/business functions and the degree of autonomy that organizational entities or subcomponents have with respect to parent organizations. Organizations that are decentralized can expect to conduct more risk assessment activities at Tier 2 and, as a result, may have a greater need to communicate within Tier 2 to identify cross-cutting threats and vulnerabilities. Decentralized organizations can still benefit from Tier 1 risk assessments and, in particular, the identification of an initial set of threat and vulnerability sources. Organization-wide risk assessments provide some initial prioritization of risks for decision makers to consider when entering the risk response step.
Organizations benefit significantly from conducting risk assessments as part of an organization-wide risk management process. However, once risk assessments are complete, it is prudent for organizations to invest some time in keeping the assessments current. Maintaining currency of risk assessments may require support from the risk monitoring step (e.g., observing changes in organizational information systems and environments of operation). Keeping risk assessments up to date provides many potential benefits such as timely, relevant information that enables senior leaders/executives to perform near real-time risk management. Maintaining risk assessments also reduces future assessment costs and supports ongoing risk monitoring efforts. Organizations may determine that conducting comprehensive risk assessments as a way of maintaining current risk assessments do not provide sufficient value. In such situations, organizations consider conducting incremental and/or differential risk assessments. Incremental risk assessments consider only new information (e.g., the effects of using a new information system on mission/business risk), whereas differential risk assessments consider how changes affect the overall risk determination. Incremental or differential risk assessments are useful if organizations require a more targeted review of risk, seek an expanded understanding of risk, or desire an expanded understanding of the risk in relation to missions/business functions.
STEP 2: RISK ASSESSMENT
Inputs and Preconditions
Inputs to the risk assessment step from the risk framing step include, for example: (i) acceptable risk assessment methodologies; (ii) the breadth and depth of analysis employed during risk assessments; (iii) the level of granularity required for describing threats; (iv) whether/how to assess external service providers; and (v) whether/how to aggregate risk assessment results from different organizational entities or mission/business functions to the organization as a whole. Organizational expectations regarding risk assessment methodologies, techniques, and/or procedures are shaped heavily by governance structures, risk tolerance, culture, trust, and life cycle processes. Prior to conducting risk assessments, organizations understand the fundamental reasons for conducting the assessments and what constitutes adequate depth and breadth for the assessments. Risk assumptions, risk constraints, risk tolerance, and priorities/trade-offs defined during the risk framing step shape how organizations use risk assessments--for example, localized applications of the risk assessments within each of the risk management tiers (i.e., governance, mission/business process, information systems) or global applications of the risk assessments across the entire organization. Risk assessments can be conducted by organizations even when some of the inputs from the risk framing step have not been received or preconditions established. However, in those situations, the quality of the risk assessment results may be affected. In addition to the risk framing step, the risk assessment step can receive inputs from the risk monitoring step, especially during mission operations and the operations/maintenance phase of the SDLC (e.g., when organizations discover new threats or vulnerabilities that require an immediate reassessment of risk). The risk assessment step can also receive inputs from the risk response step (e.g., when organizations are considering the risk of employing new technology-based solutions as alternatives for risk reduction measures). As courses of action are developed in the risk response step, a differential risk assessment may be needed to evaluate differences that each course of action makes in the overall risk determination.
THREAT AND VULNERABILITY IDENTIFICATION
TASK 2-1: Identify threats to and vulnerabilities in organizational information systems and the environments in which the systems operate.
Supplemental Guidance: Threat identification requires an examination of threat sources and events. For examining threat sources and events, organizations identify threat capabilities, intentions, and targeting information from all available sources. Organizations can leverage a number of sources for threat information at strategic or tactical levels. Threat information generated any tier can be used to inform or refine the risk-related activities in any other tier. For example, specific threats (i.e., tactics, techniques, and procedures) identified during Tier 1 threat assessments may directly affect mission/business process and architectural design decisions at Tier 2. Specific threat information generated at Tiers 2 and 3 can be used by organizations to refine threat information generated during initial threat assessments carried out at Tier 1.
Vulnerability identification occurs at all tiers. Vulnerabilities related to organizational governance (e.g., inconsistent decisions about the relative priorities of mission/business processes, selection of incompatible implementations of security controls) as well as vulnerabilities related to external dependencies (e.g., electrical power, supply chain, telecommunications), are most effectively identified at Tier 1. However, most vulnerability identification occurs at Tiers 2 and 3. At Tier 2, process and architecture-related vulnerabilities (e.g., exploitable weaknesses or deficiencies in mission/business processes, enterprise/information security architectures) are more likely to be identified. At Tier 3, information system vulnerabilities are the primary focus. These vulnerabilities are commonly found in the hardware, software, and firmware components of information systems or in the environments in which the systems operate. Vulnerabilities associated with architectural design and mission/business processes can have a greater impact on the ability of organizations to successfully carry out missions and business functions due to the potential impact across multiple information systems and mission environments. The refined vulnerability assessments conducted at Tiers 2 and 3 are shared with organizational personnel responsible for assessing risks more strategically. Vulnerability assessments conducted at Tier 2 and Tier 3 have the opportunity to evaluate additional related variables such as location, proximity to other high risk assets (physical or logical), and resource considerations related to operational environments. Information specific to operational environments allows for more useful and actionable assessment results. Vulnerability identification can be accomplished at a per-individual weakness/deficiency level or at a root-cause level. When selecting between approaches, organizations consider whether the overall objective is identifying each specific instance or symptom of a problem or understanding the underlying root causes of problems. Understanding specific exploitable weaknesses or deficiencies is helpful when problems are first identified or when quick fixes are required. This specific understanding also provides organizations with necessary sources of information for eventually diagnosing potential root causes of problems, especially those problems that are systemic in nature.
Organizations with more established enterprise and information security architectures and mature life cycle processes have outputs that can be used to inform risk assessment processes. Risk assumptions, constraints, tolerances, priorities, and trade-offs used for developing enterprise or information security architectures can be useful sources of information for initial risk assessment activities. Risk assessments conducted to support the development of segment or solution architectures may also serve as information sources for the identification of threats and vulnerabilities. Another factor influencing threat and vulnerability identification is organizational culture. Organizations that promote free and open communications and non-retribution for sharing adverse information tend to foster greater openness from individuals working within those organizations. Frequently, organizational personnel operating at Tiers 2 and 3 have valuable information and can make meaningful contributions in the area of threat and vulnerability identification. The culture of organizations influences the willingness of personnel to communicate potential threat and vulnerability information, which ultimately affects the quality and quantity of the threats/vulnerabilities identified.
TASK 2-2: Determine the risk to organizational operations and assets, individuals, other organizations, and the Nation if identified threats exploit identified vulnerabilities.
Supplemental Guidance: Organizations determine risk by considering the likelihood that known threats exploit known vulnerabilities and the resulting consequences or adverse impacts (i.e., magnitude of harm) if such exploitations occur. Organizations use threat and vulnerability information together with likelihood and consequences/impact information to determine risk either qualitatively or quantitatively. Organizations can employ a variety of approaches to determine the likelihood of threats exploiting vulnerabilities. Likelihood determinations can be based on either threat assumptions or actual threat information (e.g., historical data on cyber attacks, historical data on earthquakes, or specific information on adversary capabilities, intentions, and targeting). When specific and credible threat information is available (e.g., types of cyber attacks, cyber attack trends, frequencies of attacks), organizations can use empirical data and statistical analyses to determine more specific probabilities of threats occurring. Assessment of likelihood can also be influenced by whether vulnerability identification occurred at the individual weakness or deficiency level or at the root-cause level. The relative ease/difficulty of vulnerability exploitation, the sophistication of adversaries, and the nature of operational environments all influence the likelihood that threats exploit vulnerabilities. Organizations can characterize adverse impacts by security objective (e.g., loss of confidentiality, integrity, or availability). However, to maximize usefulness, adverse impact is expressed in or translated into terms of organizational missions, business functions, and stakeholders.
Risk Determination and Uncertainty
Risk determinations require analysis of threat, vulnerability, likelihood, and impact-related information. Organizations also need to examine mission/business vulnerability to threats for which no safeguards/countermeasures (i.e., security controls or viable implementations of controls) exist when evaluating risk. The nature of the inputs provided to this step (e.g., general, specific, strategic, tactical) directly affects the type of outputs or risk determinations made. Organizations also consider additional insights related to the anticipated time frames associated with particular risks. Time horizons associated with potential threats can shape future risk responses (e.g., risk may not be a concern if the time horizon for the risk is in the distant future).
Organizational guidance for determining risk under uncertainty indicates how combinations of likelihood and impact are combined into a determination of the risk level or risk score/rating. Organizations need to understand the type and amount of uncertainty surrounding risk decisions so that risk determinations can be understood. During the risk framing step, organizations may have provided guidance on how to analyze risk and how to determine risk when a high degree of uncertainty exists. Uncertainty is particularly a concern when the risk assessment considers advanced persistent threats, for which analysis of interacting vulnerabilities may be needed, the common body of knowledge is sparse, and past behavior may not be predictive.
While threat and vulnerability determinations apply frequently to missions and business functions, the specific requirements associated with the missions/business functions, including the environments of operation, may lead to different assessment results. Different missions, business functions, and environments of operation can lead to differences in the applicability of specific threat information considered and the likelihood of threats causing potential harm. Understanding the threat component of the risk assessment requires insight into the particular threats facing specific missions or business functions. Such awareness of threats includes understanding the capability, intent, and targeting of particular adversaries. The risk tolerance of organizations and underlying beliefs associated with how the risk tolerance is formed (including the culture within organizations) may shape the perception of impact and likelihood in the context of identified threats and vulnerabilities.
Even with the establishment of explicit criteria, risk assessments are influenced by organizational culture and the personal experiences and accumulated knowledge of the individuals conducting the assessments. As a result, assessors of risk can reach different conclusions from the same information. This diversity of perspective can enrich the risk assessment process and provide decision makers with a greater array of information and potentially fewer biases. However, such diversity may also lead to risk assessments that are inconsistent. Organizationally-defined and applied processes provide the means to identify inconsistent practices and include processes to identify and resolve such inconsistencies.
Outputs and Post Conditions
The output of the risk assessment step is a determination of risk to organizational operations (i.e., mission, functions, image, and reputation), organizational assets, individuals, other organizations, and the Nation. Depending on the approach that organizations take, either the overall risk to the organization or the inputs used to determine risk may be communicated to the decision makers responsible for risk response. In certain situations, there are recurring cycles between the risk assessment step and the risk response step until particular objectives are achieved. Based on the course of action selected during the risk response step, some residual risk may remain. Under certain circumstances, the level of residual risk could trigger a reassessment of risk. This reassessment is typically incremental (assessing only the new information) and differential (assessing how the new information changes the overall risk determination).
The aggregation of risk assessment results from all three tiers drives the management of portfolios of risks undertaken by organizations. Identified risks common to more than one mission/business function within organizations may also be the source for future assessment activities at Tier 1, such as root-cause analysis. Gaining a better understanding of the reasons why certain risks are more common or frequent assists decision makers in selecting risk responses that address underlying (or root-cause) problems instead of solely focusing on the surface issues surrounding the existence of the risks. The results of risk assessments can also shape future design and development decisions related to enterprise architecture, information security architecture, and organizational information systems. The extent to which missions and business functions are vulnerable to a set of identified threats and the relative ease with which those threats can be exploited, contribute to the risk-related information provided to senior leaders/executives.
Outputs from the risk assessment step can be useful inputs to the risk framing and risk monitoring steps. For example, risk determinations can result in revisiting the organizational risk tolerance established during the risk framing step. Organizations can also choose to use information from the risk assessment step to inform the risk monitoring step. For example, risk assessments can include recommendations to monitor specific elements of risk (e.g., threat sources) so that if certain thresholds are crossed, previous risk assessment results can be reviewed and updated, as appropriate. Particular thresholds established as part of risk monitoring programs can also serve as the basis for reassessments of risk. If organizations establish criteria as a part of the risk framing step for when risk assessment results do not warrant risk responses, then assessment results could be fed directly to the risk monitoring step as a source of input.
3.3 RESPONDING TO RISK
Risk response identifies, evaluates, decides on, and implements appropriate courses of action to accept, avoid, mitigate, share, or transfer risk to organizational operations and assets, individuals, other organizations, and the Nation, resulting from the operation and use of information systems. Identifying and analyzing alternative courses of action typically occurs at Tier 1 or Tier 2. This is due to the fact that alternative courses of action (i.e., potential risk responses) are evaluated in terms of anticipated organization-wide impacts and the ability of organizations to continue to successfully carry out organizational missions and business functions. Decisions to employ risk response measures organization-wide are typically made at Tier 1, although the decisions are informed by risk-related information from the lower tiers. At Tier 2, alternative courses of action are evaluated in terms of anticipated impacts on organizational missions/business functions, the associated mission/business processes supporting the missions/business functions, and resource requirements. At Tier 3, alternative courses of action tend to be evaluated in terms of the system development life cycle or the maximum amount of time available for implementing the selected course(s) of action. The breadth of potential risk responses is a major factor for whether the activity is carried out at Tier 1, Tier 2, or Tier 3. Risk decisions are influenced by organizational risk tolerance developed as part of risk framing activities at Tier 1. Organizations can implement risk decisions at any of the risk management tiers with different objectives and utility of information produced.
STEP 3: RISK RESPONSE
Inputs and Preconditions
Inputs from the risk assessment and risk framing steps include: (i) identification of threat sources and threat events; (ii) identification of vulnerabilities that are subject to exploitation; (iii) estimates of potential consequences and/or impact if threats exploit vulnerabilities; (iv) likelihood estimates that threats exploit vulnerabilities; (v) a determination of risk to organizational operations (i.e., mission, functions, image, and reputation), organizational assets, individuals, other organizations, and the Nation; (vi) risk response guidance from the organizational risk management strategy (see Appendix H); and (vii) the general organizational directions and guidance on appropriate responses to risk. In addition to the risk assessment and risk framing steps, the risk response step can receive inputs from the risk monitoring step (e.g., when organizations experience a breach or compromise to their information systems or environments of operation that require an immediate response to address the incident and reduce additional risk that results from the event). The risk response step can also receive inputs from the risk framing step (e.g., when organizations are required to deploy new safeguards and countermeasures in their information systems based on security requirements in new legislation or OMB policies). The risk framing step also directly shapes the resource constraints associated with selecting an appropriate course of action. Additional preconditions established at the risk framing step may include: (i) constraints based on architecture and previous investments; (ii) organizational preferences and tolerances; (iii) the expected effectiveness at mitigating risk (including how effectiveness is measured and monitored); and (iv) the time horizon for the risk (e.g., current risk, projected risk--that is, a risk expected to arise in the future based on the results of threat assessments or a planned changes in missions, business functions, enterprise architecture, information security architecture, or aspects of legal or regulatory compliance).
RISK RESPONSE IDENTIFICATION
TASK 3-1: Identify alternative courses of action to respond to risk determined during the risk assessment.
Supplemental Guidance: Organizations can respond to risk in a variety of ways. These include: (i) risk acceptance; (ii) risk avoidance; (iii) risk mitigation; (iv) risk sharing; (v) risk transfer; or (v) a combination of the above. A course of action is a time-phased or situation-dependent combination of risk response measures. For example, in an emergency situation, organizations might accept the risk associated with unfiltered connection to an external communications provider for a limited time; then avoid risk by cutting the connection; mitigate risk in the near-term by applying security controls to search for malware or evidence of unauthorized access to information that occurred during the period of unfiltered connection; and finally mitigate risk long-term by applying controls to handle such connections more securely.
Risk acceptance is the appropriate risk response when the identified risk is within the organizational risk tolerance. Organizations can accept risk deemed to be low, moderate, or high depending on particular situations or conditions. For example, organizations with data centers residing in the northeastern portion of the United States may opt to accept the risk of earthquakes based on known likelihood of earthquakes and data center vulnerability to damage by earthquakes. Organizations accept the fact that earthquakes are possible, but given the infrequency of major earthquakes in that region of the country, believe it is not cost-effective to address such risk--that is, the organizations have determined that risk associated with earthquakes is low. Conversely, organizations may accept substantially greater risk (in the moderate/high range) due to compelling mission, business, or operational needs. For example, federal agencies may decide to share very sensitive information with first responders who do not typically have access to such information due to time-sensitive needs to stop pending terrorist attacks, even though the information is not itself perishable with regard to risk through loss of confidentiality. Organizations typically make determinations regarding the general level of acceptable risk and the types of acceptable risk with consideration of organizational priorities and trade-offs between: (i) near-term mission/business needs and potential for longer-term mission/business impacts; and (ii) organizational interests and the potential impacts on individuals, other organizations, and the Nation.
Risk avoidance may be the appropriate risk response when the identified risk exceeds the organizational risk tolerance. Organizations may conduct certain types of activities or employ certain types of information technologies that result in risk that is unacceptable. In such situations, risk avoidance involves taking specific actions to eliminate the activities or technologies that are the basis for the risk or to revise or reposition these activities or technologies in the organizational mission/business processes to avoid the potential for unacceptable risk. For example, organizations planning to employ networked connections between two domains, may determine through risk assessments that there is unacceptable risk in establishing such connections. Organizations may also determine that implementing effective safeguards and countermeasures (e.g., cross-domain solutions) is not practical in the given circumstances. Thus, the organizations decide to avoid the risk by eliminating the electronic or networked connections and employing an "air gap" with a manual connection processes (e.g., data transfers by secondary storage devices).
Risk mitigation, or risk reduction, is the appropriate risk response for that portion of risk that cannot be accepted, avoided, shared, or transferred. The alternatives to mitigate risk depend on: (i) the risk management tier and the scope of risk response decisions assigned or delegated to organizational officials at that tier (defined by the organizational governance structures); and (ii) the organizational risk management strategy and associated risk response strategies. The means used by organizations to mitigate risk can involve a combination of risk response measures across the three tiers. For example, risk mitigation can include common security controls at Tier 1, process re-engineering at Tier 2, and/or new or enhanced management, operational, or technical safeguards or countermeasures (or some combination of all three) at Tier 3. Another example of a potential risk requiring mitigation can be illustrated when adversaries have access to mobile devices (e.g., laptop computers or personal digital assistants) while users are traveling. Possible risk mitigation measures include, for example, organizational policies prohibiting transport of mobile devices to certain areas of the world or procedures for users to obtain a clean mobile device that is never allowed to connect to the organizational networks.
Risk Sharing or Transfer
Risk sharing or risk transfer is the appropriate risk response when organizations desire and have the means to shift risk liability and responsibility to other organizations. Risk transfer shifts the entire risk responsibility or liability from one organization to another organization (e.g., using insurance to transfer risk from particular organizations to insurance companies). Risk sharing shifts a portion of risk responsibility or liability to other organizations (usually organizations that are more qualified to address the risk). It is important to note that risk transfer reduces neither the likelihood of harmful events occurring nor the consequences in terms of harm to organizational operations and assets, individuals, other organizations, or the Nation. Risk sharing may be a sharing of liability or a sharing of responsibility for other, adequate risk responses such as mitigation. Therefore, the concept of risk transfer is less applicable in the public sector (e.g., federal, state, local governments) than the private sector, as liability of organizations is generally established by legislation or policy. As such, self-initiated transfers of risk by public sector organizations (as typified by purchasing insurance) are generally not possible. Risk sharing often occurs when organizations determine that addressing risk requires expertise or resources that are better provided by other organizations. For example, an identified risk might be the physical penetration of perimeters and kinetic attacks by terrorist groups and the organization decides to partner with another organization sharing the physical facility to take joint responsibility for addressing the risk from kinetic attacks.
EVALUATION OF ALTERNATIVES
TASK 3-2: Evaluate alternative courses of action for responding to risk.
Supplemental Guidance: The evaluation of alternative courses of action can include: (i) the expected effectiveness in achieving desired risk response (and how effectiveness is measured and monitored); (ii) anticipated costs throughout the expected period of time during which the course of action is followed (e.g., cost of procurement, integration into organizational processes at Tier 1 and/or Tier 2, information systems at Tier 3, training, and maintenance); and (iii) mission/business impacts. During the evaluation of alternative courses of action, trade-offs can be made explicit between near-term gains in mission/business effectiveness or efficiency and long-term risk of mission/business harm due to compromise of information or information systems that are providing this near-term benefit. For example, organizations concerned about the potential for mobile devices (e.g., laptop computers) being compromised while employees are on travel can evaluate several courses of action including: (i) providing users traveling to high-risk areas with clean laptops; (ii) removing hard drives from laptops and operate from CDs or DVDs; or (iii) having laptops go through a detailed assessment before being allowed to connect to organizational networks. The first option is highly effective as returning laptops are never connected to organizational networks. While the second option ensures that hard drives cannot be corrupted, it is not quite as effective in that it is still possible that hardware devices (e.g., motherboards) could have been compromised. The effectiveness of the third option is limited by the ability of organizations to detect potential insertion of malware into the hardware, firmware, or software. As such, it is the least effective of the three options. From a cost perspective, the first option is potentially the most expensive, depending upon the number of travelers (hence number of travel laptops) required. The second and third options are considerably less expensive. From a mission and operational perspective, the third option is the best alternative as users have access to standard laptop configurations including all applications and supporting data needed to perform tasks supporting missions and business functions. Such applications and data would not be available if the first or second option is selected. Ultimately, the evaluation of courses of action is made based on operational requirements, including information security requirements, needed for near and long term mission/business success. Budgetary constraints, consistency with investment management strategies, civil liberties, and privacy protection, are some of the important elements organizations consider when selecting appropriate courses of action. In those instances where organizations only identify a single course of action, then the evaluation is focused on whether the course of action is adequate. If the course of action is deemed inadequate, then organizations need to refine the identified course of action to address the inadequacies or develop another course of action (see Task 3-1).
In summary, a risk verses risk-response trade-off is conducted for each course of action to provide the information necessary for: (i) selecting between the courses of action; and (ii) evaluating the courses of action is in terms of response effectiveness, costs, mission/business impact, and any other factors deemed relevant to organizations. Part of risk versus risk-response trade-off considers the issue of competing resources. From an organizational perspective, this means organizations consider whether the cost (e.g., money, personnel, time) for implementing a given course of action has the potential to adversely impact other missions or business functions, and if so, to what extent. This is necessary because organizations have finite resources to employ and many competing missions/business functions across many organizational elements. Therefore, organizations assess the overall value of alternative courses of action with regard to the missions/business functions and the potential risk to each organizational element. Organizations may determine that irrespective of the mission/business function and the validity of the mission/business function risk, there are more important missions/business functions that face more significant risks, and hence have a better claim on the limited resources.
RISK RESPONSE DECISION
TASK 3-3: Decide on the appropriate course of action for responding to risk.
Supplemental Guidance: Decisions on the most appropriate course of action include some form of prioritization. Some risks may be of greater concern than other risks. In that case, more resources may need to be directed at addressing higher-priority risks than at other lower-priority risks. This does not necessarily mean that the lower-priority risks would not be addressed. Rather, it could mean that fewer resources might be directed at the lower-priority risks (at least initially), or that the lower-priority risks would be addressed at a later time. A key part of the risk decision process is the recognition that regardless of the decision, there still remains a degree of residual risk that must be addressed. Organizations determine acceptable degrees of residual risk based on organizational risk tolerance and the specific risk tolerances of particular decision makers. Impacting the decision process are some of the more intangible risk-related concepts (e.g., risk tolerance, trust, and culture). The specific beliefs and approaches that organizations embrace with respect to these risk-related concepts affect the course of action selected by decision-makers.
RISK RESPONSE IMPLEMENTATION
TASK 3-4: Implement the course of action selected to respond to risk.
Supplemental Guidance: Once a course of action is selected, organizations implement the associated risk response. Given the size and complexity of some organizations, the actual implementation of risk response measures may be challenging. Some risk response measures are tactical in nature (e.g., applying patches to identified vulnerabilities in organizational information systems) and may be implemented rather quickly. Other risk response measures may be more strategic in nature and reflect solutions that take much longer to implement. Therefore, organizations apply, and tailor as appropriate to a specific risk response course of action, the risk response implementation considerations in the risk response strategies (part of the risk management strategy developed during the risk framing step). See Appendix H, Risk Response Strategies.
Outputs and Post Conditions
The output of the risk response step is the implementation of the selected courses of action with consideration for: (i) individuals or organizational elements responsible for the selected risk response measures and specifications of effectiveness criteria (i.e., articulation of indicators and thresholds against which the effectiveness of risk response measures can be judged); (ii) dependencies of each selected risk response measure on other risk response measures; (iii) dependencies of selected risk response measures on other factors (e.g., the implementation of other planned information technology measures); (iv) timeline for implementation of risk response measures; (v) plans for monitoring the effectiveness of risk response measures; (vi) identification of risk monitoring triggers; and (vii) interim risk response measures selected for implementation, if appropriate. There are also ongoing communications and sharing of risk-related information with individuals or organizational elements impacted by the risk responses (including potential actions that may need to be taken by the individuals or organizational elements).
In addition to the risk monitoring step, outputs from the risk response step can be useful inputs to the risk framing and risk assessment steps. For example, it is possible that the analysis occurring during the evaluation of alternative courses of action may call into question some aspects of the risk response strategy that is part of the risk management strategy generated during the risk framing step. In such instances, organizations use that information to inform the risk framing step with appropriate actions taken to revisit the risk management strategy and its associated risk response strategy. Organizations might also determine during the evaluation of alternative courses of action for risk response, that some aspects of the risk assessments are incomplete or incorrect. This information can be used to inform the risk assessment step possibly resulting in further analysis or reassessments of risk.
3.4 MONITORING RISK
Risk monitoring provides organizations with the means to: (i) verify compliance; (ii) determine the ongoing effectiveness of risk response measures; and (iii) identify risk-impacting changes to organizational information systems and environments of operation. Organizations employ risk monitoring tools, techniques, and procedures to increase risk awareness--that is, helping senior leaders/executives develop a better understanding of the ongoing risk to organizational operations and assets, individuals, other organizations, and the Nation. Organizations can implement risk monitoring at any of the risk management tiers with different objectives and utility of information produced. For example, Tier 1 monitoring activities might include ongoing threat assessments and how changes in the threat space may affect Tier 2 and Tier 3 activities, including current enterprise and information security architectures and organizational information systems. Tier 2 monitoring activities might include, for example, analyses of new or current technologies either in use or considered for future use by organizations to identify exploitable weaknesses and/or deficiencies in those technologies that may affect mission/business success. Tier 3 monitoring activities focus on information systems and might include, for example, automated monitoring of standard configuration settings for information technology products, vulnerability scanning, and ongoing assessments of security controls. In addition to deciding on appropriate monitoring activities across the risk management tiers, organizations also decide how monitoring is to be conducted (e.g., automated or procedural approaches) and the frequency of monitoring activities based on, for example, the frequency with which deployed security controls change, critical items on plans of action and milestones, and risk tolerance.
STEP 4: RISK MONITORING
Inputs and Preconditions
Inputs to this step include implementation strategies for selected courses of action for risk responses and the actual implementation of selected courses of action. In addition to the risk response step, the risk monitoring step can receive inputs from the risk framing step (e.g., when organizations become aware of an advanced persistent threat reflecting a change in threat assumptions, this may result in a change in the frequency of follow on monitoring activities). The risk framing step also directly shapes the resource constraints associated with establishing and implementing an organization-wide monitoring strategy. In some instances, outputs from the risk assessment step may be useful inputs to the risk monitoring step. For example, risk assessment threshold conditions (e.g., likelihood of threats exploiting vulnerabilities) could be input to the risk monitoring step. In turn, organizations could monitor to determine if such threshold conditions are met. If threshold conditions are met, such information could be used in the risk assessment step, where it could serve as the basis for an incremental, differential risk assessment or an overall reassessment of risk to the organization.
RISK MONITORING STRATEGY
TASK 4-1: Develop a risk monitoring strategy for the organization that includes the purpose, type, and frequency of monitoring activities.
Supplemental Guidance: Organizations implement risk monitoring programs: (i) to verify that required risk response measures are implemented and that information security requirements derived from and traceable to organizational missions/business functions, federal legislation, directives, regulations, policies, and standards/guidelines, are satisfied (compliance monitoring); (ii) to determine the ongoing effectiveness of risk response measures after the measures have been implemented (effectiveness monitoring); and (iii) to identify changes to organizational information systems and the environments in which the systems operate that may affect risk (change monitoring). Determining the purpose of risk monitoring programs directly impacts the means used by organizations to conduct the monitoring activities and where monitoring occurs (i.e., at which risk management tiers). Organizations also determine the type of monitoring to be employed, including approaches that rely on automation or approaches that rely on procedural/manual activities with human intervention. Finally, organizations determine how often monitoring activities are conducted. Monitoring strategies developed at Tier 1 influence and provide direction for similar strategies developed at Tier 2 and Tier 3 including the monitoring activities associated with the Risk Management Framework at the information system level.
Compliance monitoring is employed to ensure that organizations are implementing needed risk response measures. This includes ensuring that the risk response measures selected and implemented by organizations in response to risk determinations produced from risk assessments are implemented correctly and operating as intended. Failure to implement the risk response measures selected by organizations can result in the organizations continuing to be subject to the identified risk. Compliance monitoring also includes ensuring that risk response measures required by federal mandates (e.g., legislation, directives, policies, regulations, standards) or organizational mandates (e.g., local policies, procedures, mission/business requirements) are implemented. Compliance monitoring is the easiest type of monitoring to perform because there are typically a finite set of risk response measures employed by organizations usually in the form of security controls. Such measures are typically well-defined and articulated as an output from the risk response step. The more challenging part of compliance monitoring is evaluating whether the risk response measures are implemented correctly (and in some instances continuously). Compliance monitoring also includes, as feasible, analysis as to why compliance failed. The reason for compliance failure can range from individuals failing to do their jobs correctly to the risk response measure not functioning as intended. If monitoring indicates a failure in compliance, then the response step of the risk management process is revisited. A key element of the feedback to the response step is the finding from compliance monitoring indicating the reason for the compliance failure. In some instances, compliance failures can be fixed by simply re-implementing the same risk response measures with little or no change. But in other instances, compliance failures are more complicated (e.g., the selected risk response measures are too difficult to implement or the measures did not function as expected). In such instances, it may be necessary for organizations to return to the evaluation and decision portions of the risk response step to develop different risk response measures.
Effectiveness monitoring is employed by organizations to determine if implemented risk response measures have actually been effective in reducing identified risk to the desired level. Although effectiveness monitoring is different than compliance monitoring, failure to achieve desired levels of effectiveness may be an indication that risk response measures have been implemented incorrectly or are not operating as intended. Determining the effectiveness of risk response measures is generally more challenging than determining whether the measures have been implemented correctly and are operating as intended (i.e., meeting identified compliance requirements). Risk response measures implemented correctly and operating as intended do not guarantee an effective reduction of risk. This is primarily due to: (i) the complexity of operating environments which may generate unintended consequences; (ii) subsequent changes in levels of risk or associated risk factors (e.g., threats, vulnerabilities, impact, or likelihood); (iii) inappropriate or incomplete criteria established as an output of the risk response step; and (iv) changes in information systems and environments of operation after implementation of risk response measures. This is especially true when organizations try to determine if more strategic outcomes have been achieved and for more dynamic operating environments. For example, if the desired outcome for organizations is to be less susceptible to advanced persistent threats, this may be challenging to measure since these types of threats are, by definition, very difficult to detect. Even when organizations are able to establish effectiveness criteria, it is often difficult to obtain criteria that are quantifiable. Therefore, it may become a matter of subjective judgment as to whether the implemented risk response measures are ultimately effective. Moreover, even if quantifiable effectiveness criteria are provided, it may be difficult to determine if the information provided satisfies the criteria. If organizations determine that risk response measures are not effective, then it may be necessary to return to the risk response step. Generally, for effectiveness failures, organizations cannot simply return to the implementation portion of the risk response step. Therefore, depending on the reason for the lack of effectiveness, organizations revisit all portions of the risk response step (i.e., development, evaluation, decision, and implementation) and potentially the risk assessment step. These activities may result in organizations developing and implementing entirely new risk responses.
In addition to compliance monitoring and effectiveness monitoring, organizations monitor changes to organizational information systems and the environments in which those systems operate. Monitoring changes to information systems and environments of operation is not linked directly to previous risk response measures but it is nonetheless important to detect changes that may affect the risk to organizational operations and assets, individuals, other organizations, and the Nation. Generally, such monitoring detects changes in conditions that may undermine risk assumptions (articulated in the risk framing step).
- Information System: Changes can occur in organizational information systems (including hardware, software, and firmware) that can introduce new risk or change existing risk. For example, updates to operating system software can eliminate security capabilities that existed in earlier versions, thus introducing new vulnerabilities into organizational information systems. Another example is the discovery of new system vulnerabilities that fall outside of the scope of the tools and processes available to address such vulnerabilities (e.g., vulnerabilities for which there are no established mitigations).
- Environments of Operation: The environments in which information systems operate can also change in ways that introduce new risk or change existing risk. Environmental and operational considerations include, but are not limited to, missions/business functions, threats, vulnerabilities, mission/business processes, facilities, policies, legislation, and technologies. For example, new legislation or regulations could be passed that impose additional requirements on organizations. This change might affect the risk assumptions established by organizations. Another example is a change in the threat environment that reports new tactics, techniques, procedures, or increases in the technical capabilities of adversaries. Organizations might experience reductions in available resources (e.g., personnel or funding), which in turn results in changing priorities. Organizations might also experience changes in the ownership of third-party suppliers which could affect supply chain risk. Mission changes may require that organizations revisit underlying risk assumptions. For example, an organization whose mission is to collect threat information on possible domestic terrorist attacks and share such information with appropriate federal law enforcement and intelligence agencies may have its scope changed so that the organization is responsible for also sharing some of the information with local first responders. Such a change could affect assumptions regarding the security resources such users may have at their disposal. Changes in technology may also affect the underlying risk assumptions established by organizations. Unlike other types of change, technology changes may be totally independent of organizations, but still affect the risk organizations must address. For example, improvements in computing power may undermine assumptions regarding what constitutes sufficiently strong means of authentication (e.g., number of authentication factors) or cryptographic mechanism.
Automated Versus Procedural Monitoring
Broadly speaking, organizations can conduct monitoring either by automated or procedural (i.e., manual) methods. Where automated monitoring is feasible, it should be employed because it is generally faster, more efficient, and more cost-effective than procedural monitoring. Automated monitoring is also less prone to human error. However, not all monitoring can take advantage of automation. Monitoring conducted at Tier 3 generally lends itself to automation where activities being monitored are information technology-based. Such activities can usually be detected, tracked, and monitored through the installation of appropriate software, hardware and/or firmware. Compliance monitoring can be supported by automation when the risk mitigation measures being validated are information technology-based (e.g., installation of firewalls or testing of configuration settings on desktop computers). Such automated validation can often check whether risk mitigation measures are installed and whether the installations are correct. Similarly, effectiveness monitoring may also be supported by automation. If the threshold conditions for determining the effectiveness of risk response measures are predetermined, then automation can support such effectiveness monitoring. While automation can be a supporting capability for Tiers 1 and 2, generally automation does not provide substantive insight for non-information technology-based activities which are more prevalent at those higher tiers. Activities that are not as likely to benefit from automation include, for example, the use of multiple suppliers within the supply chain, evolving environments of operation, or evaluating the promise of emerging technical capabilities in support of missions/business functions. Where automated monitoring is not available, organizations employ procedural monitoring and/or analysis.
Frequency of Monitoring
The frequency of risk monitoring (whether automated or procedural) is driven by organizational missions/business functions and the ability of organizations to use the monitoring results to facilitate greater situational awareness. An increased level of situational awareness of the security state of organizational information systems and environments of operation helps organizations develop a better understanding of risk. Monitoring frequency is also driven by other factors, for example: (i) the anticipated frequency of changes in organizational information systems and operating environments; (ii) the potential impact of risk if not properly addressed through appropriate response measures; and (iii) the degree to which the threat space is changing. The frequency of monitoring can also be affected by the type of monitoring conducted (i.e., automated versus procedural approaches). Depending on the frequency of monitoring required by organizations, in most situations, continuous monitoring is most efficient and cost-effective when automated monitoring is employed. Continuous monitoring can provide significant benefits, especially in situations where such monitoring limits the opportunities for adversaries to gain a foothold within organizations (either through information systems or the environments in which those systems operate). When procedural monitoring is employed by organizations, it is generally not efficient to perform the monitoring with the frequency that automation allows. In some instances, infrequent monitoring is not a major issue. For example, missions/business functions, facilities, legislation, policies, and technologies tend to change on a more gradual basis and as such, do not lend themselves to frequent monitoring (i.e., automated monitoring on a near real-time basis). Instead, these types of changes are better suited to condition/event-based monitoring--that is, if organizational missions change, then monitoring of such changes is appropriate to determine if the changes have any impact on risk.
TASK 4-2: Monitor organizational information systems and environments of operation on an ongoing basis to verify compliance, determine effectiveness of risk response measures, and identify changes.
Supplemental Guidance: Once organizations complete the development of their monitoring strategies, the strategies are implemented organization-wide. Because there are so many diverse aspects of monitoring, not all aspects of monitoring may be performed, or they may be performed at different times. The particular aspects of monitoring that are performed are dictated largely by the assumptions, constraints, risk tolerance, and priorities/trade-offs established by organizations during the risk framing step. For example, while organizations might desire to conduct all forms of monitoring (i.e., compliance, effectiveness, and change), the constraints imposed upon the organizations may allow only compliance monitoring that can be readily automated at Tier 3. If multiple aspects of monitoring can be supported, the output from the risk framing step helps organizations to determine the degree of emphasis and level of effort to place on the various monitoring activities.
As noted above, not all monitoring activities are conducted at the same tiers, for the same purpose, at the same time, or using the same techniques. However, it is important that organizations attempt to coordinate the various monitoring activities. Coordination of monitoring activities facilitates the sharing of risk-related information that may be useful for organizations in providing early warning, developing trend information, or allocating risk response measures in a timely and efficient manner. If monitoring is not coordinated, then the benefit of monitoring may be reduced, and could undermine the overall effort to identify and address risk. As feasible, organizations implement the various monitoring activities in a manner that maximizes the overall goal of monitoring, looking beyond the limited goals of particular monitoring activities.
Outputs and Post Conditions
The output from the risk monitoring step is the information generated by: (i) verifying that required risk response measures are implemented and that information security requirements derived from and traceable to organizational missions/business functions, federal legislation, directives, regulations, policies, and standards/guidelines, are satisfied; (ii) determining the ongoing effectiveness of risk response measures; and (iii) identifying changes to organizational information systems and environments of operation. Outputs from the risk monitoring step can be useful inputs to the risk framing, risk assessment, and risk response steps. For example, compliance monitoring results may require that organizations revisit the implementation portion of the risk response step, while effectiveness monitoring results may require that organizations revisit the entire risk response step. The results of monitoring for changes to information systems and environments of operation may require organizations to revisit the risk assessment step. The results of the risk monitoring step can also serve the risk framing step (e.g., when organizations discover new threats or vulnerabilities that affect changes in organizational risk assumptions, risk tolerance, and/or priorities/trade-offs).
- ↑ 54 The Risk Management Framework (RMF) which operates primarily at Tier 3 is described in NIST Special Publication 800-37.
- ↑ 55 Draft NIST Special Publication 800-30, Revision 1, provides guidance on conducting risk assessments (including incremental or differential risk assessments) across all three tiers in the multitiered risk management approach.
- ↑ 56 A course of action is a time-phased or situation-dependent combination of risk response measures. A risk response measure is a specific action taken to respond to an identified risk. Risk response measures can be separately managed and can include, for example, the implementation of security controls to mitigate risk, promulgation of security policies to avoid risk or to accept risk in specific circumstances, and organizational agreements to share or transfer risk.
- ↑ 57 Compliance verification ensures that organizations have implemented required risk response measures and that information security requirements derived from and traceable to organizational missions/business functions, federal legislation, directives, regulations, policies, and standards/guidelines are satisfied.
- ↑ 58 Draft NIST Special Publication 800-137 provides guidance on monitoring organizational information systems and environments of operation.