NIST SP 800-39 Appendix B
COMMON TERMS AND DEFINITIONS
This appendix provides definitions for security terminology used within Special Publication 800-39. The terms in the glossary are consistent with the terms used in the suite of FISMA-related security standards and guidelines developed by NIST. Unless otherwise stated, all terms used in this publication are also consistent with the definitions contained in the CNSS Instruction 4009, National Information Assurance (IA) Glossary.
Adequate Security [OMB Circular A-130, Appendix III]
Security commensurate with the risk and magnitude of harm resulting from the loss, misuse, or unauthorized access to or modification of information.
Advanced Persistent Threat
An adversary that possesses sophisticated levels of expertise and significant resources which allow it to create opportunities to achieve its objectives by using multiple attack vectors (e.g., cyber, physical, and deception). These objectives typically include establishing and extending footholds within the information technology infrastructure of the targeted organizations for purposes of exfiltrating information, undermining or impeding critical aspects of a mission, program, or organization; or positioning itself to carry out these objectives in the future. The advanced persistent threat: (i) pursues its objectives repeatedly over an extended period of time; (ii) adapts to defenders' efforts to resist it; and (iii) is determined to maintain the level of interaction needed to execute its objectives.
See Executive Agency.
See Security Control Assessment.
See Security Control Assessor.
Assurance [CNSSI 4009]
Measure of confidence that the security features, practices, procedures, and architecture of an information system accurately mediates and enforces the security policy.
Assurance [NIST SP 800-53]
Grounds for confidence that the set of intended security controls in an information system are effective in their application.
Assurance Case [Software Engineering Institute, Carnegie Mellon University]
A structured set of arguments and a body of evidence showing that an information system satisfies specific claims with respect to a given quality attribute.
Authentication [FIPS 200]
Verifying the identity of a user, process, or device, often as a prerequisite to allowing access to resources in an information system.
The property of being genuine and being able to be verified and trusted; confidence in the validity of a transmission, a message, or message originator. See Authentication.
Authorization (to operate)
The official management decision given by a senior organizational official to authorize operation of an information system and to explicitly accept the risk to organizational operations (including mission, functions, image, or reputation), organizational assets, individuals, other organizations, and the Nation based on the implementation of an agreed-upon set of security controls.
Authorization Boundary [NIST SP 800-37]
All components of an information system to be authorized for operation by an authorizing official and excludes separately authorized systems, to which the information system is connected.
Authorizing Official [CNSSI 4009]
Senior (federal) official or executive with the authority to formally assume responsibility for operating an information system at an acceptable level of risk to organizational operations (including mission, functions, image, or reputation), organizational assets, individuals, other organizations, and the Nation.
Availability [44 U.S.C., Sec. 3542]
Ensuring timely and reliable access to and use of information.
Chief Information Officer [PL 104-106, Sec. 5125(b)]
Agency official responsible for:
(i) Providing advice and other assistance to the head of the executive agency and other senior management personnel of the agency to ensure that information technology is acquired and information resources are managed in a manner that is consistent with laws, Executive Orders, directives, policies, regulations, and priorities established by the head of the agency;
(ii) Developing, maintaining, and facilitating the implementation of a sound and integrated information technology architecture for the agency; and
(iii) Promoting the effective and efficient design and operation of all major information resources management processes for the agency, including improvements to work processes of the agency.
Chief Information Security Officer
See Senior Agency Information Security Officer.
Classified National Security Information [CNSSI 4009]
Information that has been determined pursuant to Executive Order 13526 or any predecessor order to require protection against unauthorized disclosure and is marked to indicate its classified status when in documentary form.
Common Control [NIST SP 800-37]
A security control that is inherited by one or more organizational information systems. See Security Control Inheritance.
Common Control Provider [NIST SP 800-37]
An organizational official responsible for the development, implementation, assessment, and monitoring of common controls (i.e., security controls inherited by information systems).
Compensating Security Control [CNSSI 4009]
A management, operational, and/or technical control (i.e., safeguard or countermeasure) employed by an organization in lieu of a recommended security control in the low, moderate, or high baselines that provides equivalent or comparable protection for an information system.
Confidentiality [44 U.S.C., Sec. 3542]
Preserving authorized restrictions on information access and disclosure, including means for protecting personal privacy and proprietary information.
Course of Action (Risk Response)
A time-phased or situation-dependent combination of risk response measures.
Cyber Attack [CNSSI 4009]
An attack, via cyberspace, targeting an enterprise's use of cyberspace for the purpose of disrupting, disabling, destroying, or maliciously controlling a computing environment/infrastructure; or destroying the integrity of the data or stealing controlled information.
Cyber Security [CNSSI 4009]
The ability to protect or defend the use of cyberspace from cyber attacks.
Cyberspace [CNSSI 4009]
A global domain within the information environment consisting of the interdependent network of information systems infrastructures including the Internet, telecommunications networks, computer systems, and embedded processors and controllers.
Defense-in-Breadth [CNSSI 4009]
A planned, systematic set of multidisciplinary activities that seek to identify, manage, and reduce risk of exploitable vulnerabilities at every stage of the system, network, or subcomponent life cycle (system, network, or product design and development; manufacturing; packaging; assembly; system integration; distribution; operations; maintenance; and retirement).
Defense-in-Depth [CNSSI 4009]
Information security strategy integrating people, technology, and operations capabilities to establish variable barriers across multiple layers and missions of the organization.
Enterprise [CNSSI 4009]
An organization with a defined mission/goal and a defined boundary, using information systems to execute that mission, and with responsibility for managing its own risks and performance. An enterprise may consist of all or some of the following business aspects: acquisition, program management, financial management (e.g., budgets), human resources, security, and information systems, information and mission management. See Organization.
Enterprise Architecture [CNSSI 4009]
The description of an enterprise's entire set of information systems: how they are configured, how they are integrated, how they interface to the external environment at the enterprise's boundary, how they are operated to support the enterprise mission, and how they contribute to the enterprise's overall security posture.
Environment of Operation [NIST SP 800-37]
The physical surroundings in which an information system processes, stores, and transmits information.
Executive Agency [41 U.S.C., Sec. 403]
An executive department specified in 5 U.S.C., Sec. 101; a military department specified in 5 U.S.C., Sec. 102; an independent establishment as defined in 5 U.S.C., Sec. 104(1); and a wholly owned Government corporation fully subject to the provisions of 31 U.S.C., Chapter 91.
See Executive Agency.
Federal Information System [40 U.S.C., Sec. 11331]
An information system used or operated by an executive agency, by a contractor of an executive agency, or by another organization on behalf of an executive agency.
Hybrid Security Control [NIST SP 800-53]
A security control that is implemented in an information system in part as a common control and in part as a system-specific control. See Common Control and System-Specific Security Control.
An assessment object that includes people applying specifications, mechanisms, or activities.
Industrial Control System
An information system used to control industrial processes such as manufacturing, product handling, production, and distribution. Industrial control systems include supervisory control and data acquisition systems used to control geographically dispersed assets, as well as distributed control systems and smaller control systems using programmable logic controllers to control localized processes.
Information [CNSSI 4009]
Any communication or representation of knowledge such as facts, data, or opinions in any medium or form, including textual, numerical, graphic, cartographic, narrative, or audiovisual.
Information [FIPS 199]
An instance of an information type.
Information Owner [CNSSI 4009]
Official with statutory or operational authority for specified information and responsibility for establishing the controls for its generation, classification, collection, processing, dissemination, and disposal. See Information Steward.
Information Resources [44 U.S.C., Sec. 3502]
Information and related resources, such as personnel, equipment, funds, and information technology.
Information Security [44 U.S.C., Sec. 3542]
The protection of information and information systems from unauthorized access, use, disclosure, disruption, modification, or destruction in order to provide confidentiality, integrity, and availability.
Information Security Architecture
An embedded, integral part of the enterprise architecture that describes the structure and behavior for an enterprise's security processes, information security systems, personnel and organizational sub-units, showing their alignment with the enterprise's mission and strategic plans.
Information Security Program Plan [NIST SP 800-53]
Formal document that provides an overview of the security requirements for an organization-wide information security program and describes the program management controls and common controls in place or planned for meeting those requirements.
Information Steward [CNSSI 4009]
An agency official with statutory or operational authority for specified information and responsibility for establishing the controls for its generation, collection, processing, dissemination, and disposal.
Information System [44 U.S.C., Sec. 3502]
A discrete set of information resources organized for the collection, processing, maintenance, use, sharing, dissemination, or disposition of information.
Information System Boundary
See Authorization Boundary.
Information System Owner (Information System Program Manager)
Official responsible for the overall procurement, development, integration, modification, or operation and maintenance of an information system.
Information System Resilience
The ability of an information system to continue to: (i) operate under adverse conditions or stress, even if in a degraded or debilitated state, while maintaining essential operational capabilities; and (ii) recover to an effective operational posture in a time frame consistent with mission needs.
Information System Security Officer
Individual assigned responsibility by the senior agency information security officer, authorizing official, management official, or information system owner for maintaining the appropriate operational security posture for an information system or program.
Information Security Risk
The risk to organizational operations (including mission, functions, image, reputation), organizational assets, individuals, other organizations, and the Nation due to the potential for unauthorized access, use, disclosure, disruption, modification, or destruction of information and/or information systems.
Information System-Related Security Risks
Risks that arise through the loss of confidentiality, integrity, or availability of information or information systems and consider impacts to the organization (including assets, mission, functions, image, or reputation), individuals, other organizations, and the Nation. See Risk.
Information Technology [40 U.S.C., Sec. 1401]
Any equipment or interconnected system or subsystem of equipment that is used in the automatic acquisition, storage, manipulation, management, movement, control, display, switching, interchange, transmission, or reception of data or information by the executive agency.
For purposes of the preceding sentence, equipment is used by an executive agency if the equipment is used by the executive agency directly or is used by a contractor under a contract with the executive agency which: (i) requires the use of such equipment; or (ii) requires the use, to a significant extent, of such equipment in the performance of a service or the furnishing of a product.
The term information technology includes computers, ancillary equipment, software, firmware, and similar procedures, services (including support services), and related resources.
Information Type [FIPS 199]
A specific category of information (e.g., privacy, medical, proprietary, financial, investigative, contractor sensitive, security management) defined by an organization or in some instances, by a specific law, Executive Order, directive, policy, or regulation.
Integrity [44 U.S.C., Sec. 3542]
Guarding against improper information modification or destruction, and includes ensuring information non-repudiation and authenticity.
Management Controls [FIPS 200]
The security controls (i.e., safeguards or countermeasures) for an information system that focus on the management of risk and the management of information system security.
National Security System [44 U.S.C., Sec. 3542]
Any information system (including any telecommunications system) used or operated by an agency or by a contractor of an agency, or other organization on behalf of an agency (i) the function, operation, or use of which involves intelligence activities; involves cryptologic activities related to national security; involves command and control of military forces; involves equipment that is an integral part of a weapon or weapons system; or is critical to the direct fulfillment of military or intelligence missions (excluding a system that is to be used for routine administrative and business applications, for example, payroll, finance, logistics, and personnel management applications); or (ii) is protected at all times by procedures established for information that have been specifically authorized under criteria established by an Executive Order or an Act of Congress to be kept classified in the interest of national defense or foreign policy.
Operational Controls [FIPS 200]
The security controls (i.e., safeguards or countermeasures) for an information system that are primarily implemented and executed by people (as opposed to systems).
Organization [FIPS 200, Adapted]
An entity of any size, complexity, or positioning within an organizational structure (e.g., a federal agency or, as appropriate, any of its operational elements). See Enterprise.
Plan of Action and Milestones [OMB Memorandum 02-01]
A document that identifies tasks needing to be accomplished. It details resources required to accomplish the elements of the plan, any milestones in meeting the tasks, and scheduled completion dates for the milestones.
Mutual agreement among participating organizations to accept each other's security assessments in order to reuse information system resources and/or to accept each other's assessed security posture in order to share information.
See Information System Resilience.
Risk [CNSSI 4009]
A measure of the extent to which an entity is threatened by a potential circumstance or event, and typically a function of: (i) the adverse impacts that would arise if the circumstance or event occurs; and (ii) the likelihood of occurrence.
[Note: Information system-related security risks are those risks that arise from the loss of confidentiality, integrity, or availability of information or information systems and reflect the potential adverse impacts to organizational operations (including mission, functions, image, or reputation), organizational assets, individuals, other organizations, and the Nation.]
The process of identifying risks to organizational operations (including mission, functions, image, reputation), organizational assets, individuals, other organizations, and the Nation, resulting from the operation of an information system.
Part of risk management, incorporates threat and vulnerability analyses, and considers mitigations provided by security controls planned or in place.
Synonymous with risk analysis.
Risk Executive (Function) [CNSSI 4009]
An individual or group within an organization that helps to ensure that: (i) security risk-related considerations for individual information systems, to include the authorization decisions for those systems, are viewed from an organization-wide perspective with regard to the overall strategic goals and objectives of the organization in carrying out its missions and business functions; and (ii) managing risk from individual information systems is consistent across the organization, reflects organizational risk tolerance, and is considered along with other organizational risks affecting mission/business success.
Risk Management [CNSSI 4009, adapted]
The program and supporting processes to manage information security risk to organizational operations (including mission, functions, image, reputation), organizational assets, individuals, other organizations, and the Nation, and includes: (i) establishing the context for risk-related activities; (ii) assessing risk; (iii) responding to risk once determined; and (iv) monitoring risk over time.
Risk Mitigation [CNSSI 4009]
Prioritizing, evaluating, and implementing the appropriate risk-reducing controls/countermeasures recommended from the risk management process.
Maintaining ongoing awareness of an organization's risk environment, risk management program, and associated activities to support risk decisions.
Accepting, avoiding, mitigating, sharing, or transferring risk to organizational operations (i.e., mission, functions, image, or reputation), organizational assets, individuals, other organizations, or the Nation.
Risk Response Measure
A specific action taken to respond to an identified risk.
Root Cause Analysis
A principle-based, systems approach for the identification of underlying causes associated with a particular set of risks.
Security Authorization (to Operate)
See Authorization (to operate).
The process of determining the security category for information or an information system. Security categorization methodologies are described in CNSS Instruction 1253 for national security systems and in FIPS 199 for other than national security systems.
Security Control Assessment [CNSSI 4009, Adapted]
The testing and/or evaluation of the management, operational, and technical security controls to determine the extent to which the controls are implemented correctly, operating as intended, and producing the desired outcome with respect to meeting the security requirements for an information system or organization.
Security Control Assessor
The individual, group, or organization responsible for conducting a security control assessment.
Security Control Baseline [CNSSI 4009]
The set of minimum security controls defined for a low-impact, moderate-impact, or high-impact information system.
Security Control Enhancements
Statements of security capability to: (i) build in additional, but related, functionality to a basic control; and/or (ii) increase the strength of a basic control.
Security Control Inheritance [CNSSI 4009]
A situation in which an information system or application receives protection from security controls (or portions of security controls) that are developed, implemented, assessed, authorized, and monitored by entities other than those responsible for the system or application; entities either internal or external to the organization where the system or application resides. See Common Control.
Security Controls [FIPS 199, CNSSI 4009]
The management, operational, and technical controls (i.e., safeguards or countermeasures) prescribed for an information system to protect the confidentiality, integrity, and availability of the system and its information.
Security Impact Analysis [NIST SP 800-37]
The analysis conducted by an organizational official to determine the extent to which changes to the information system have affected the security state of the system.
Confidentiality, integrity, or availability.
[FIPS 199] Security Plan [NIST SP 800-18]
Formal document that provides an overview of the security requirements for an information system or an information security program and describes the security controls in place or planned for meeting those requirements.
See System Security Plan or Information Security Program Plan.
Security Policy [CNSSI 4009]
A set of criteria for the provision of security services.
Security Requirements [FIPS 200]
Requirements levied on an information system that are derived from applicable laws, Executive Orders, directives, policies, standards, instructions, regulations, procedures, or organizational mission/business case needs to ensure the confidentiality, integrity, and availability of the information being processed, stored, or transmitted.
Senior Agency Information Security Officer [44 U.S.C., Sec. 3544]
Official responsible for carrying out the Chief Information Officer responsibilities under FISMA and serving as the Chief Information Officer's primary liaison to the agency's authorizing officials, information system owners, and information system security officers.
[Note: Organizations subordinate to federal agencies may use the term Senior Information Security Officer or Chief Information Security Officer to denote individuals filling positions with similar responsibilities to Senior Agency Information Security Officers.]
Senior Information Security
See Senior Agency Information Security Officer.
A major subdivision or component of an information system consisting of information, information technology, and personnel that performs one or more specific functions.
Supplementation (Security Controls)
The process of adding security controls or control enhancements to a security control baseline from NIST Special Publication 800-53 or CNSS Instruction 1253 in order to adequately meet the organization's risk management needs.
See Information System.
System Security Plan [NIST SP 800-18]
Formal document that provides an overview of the security requirements for an information system and describes the security controls in place or planned for meeting those requirements.
System-Specific Security Control [NIST SP 800-37]
A security control for an information system that has not been designated as a common control or the portion of a hybrid control that is to be implemented within an information system.
Tailoring [NIST SP 800-53, CNSSI 4009]
The process by which a security control baseline is modified based on: (i) the application of scoping guidance; (ii) the specification of compensating security controls, if needed; and (iii) the specification of organization-defined parameters in the security controls via explicit assignment and selection statements.
Tailored Security Control Baseline
A set of security controls resulting from the application of tailoring guidance to the security control baseline. See Tailoring.
Technical Controls [FIPS 200]
Security controls (i.e., safeguards or countermeasures) for an information system that are primarily implemented and executed by the information system through mechanisms contained in the hardware, software, or firmware components of the system.
Threat [CNSSI 4009]
Any circumstance or event with the potential to adversely impact organizational operations (including mission, functions, image, or reputation), organizational assets, individuals, other organizations, or the Nation through an information system via unauthorized access, destruction, disclosure, modification of information, and/or denial of service.
Threat Assessment [CNSSI 4009]
Process of formally evaluating the degree of threat to an information system or enterprise and describing the nature of the threat.
Threat Source [CNSSI 4009]
The intent and method targeted at the intentional exploitation of a vulnerability or a situation and method that may accidentally exploit a vulnerability.
Trustworthiness [CNSSI 4009]
The attribute of a person or enterprise that provides confidence to others of the qualifications, capabilities, and reliability of that entity to perform specific tasks and fulfill assigned responsibilities.
Vulnerability [CNSSI 4009]
Weakness in an information system, system security procedures, internal controls, or implementation that could be exploited by a threat source.
Vulnerability Assessment [CNSSI 4009]
Systematic examination of an information system or product to determine the adequacy of security measures, identify security deficiencies, provide data from which to predict the effectiveness of proposed security measures, and confirm the adequacy of such measures after implementation.