connected system
163531·updated Aug 30, 2026Any information system, application, or infrastructure component that lies **outside** a given system's authorization boundary yet maintains a data-flow, network, or processing link to it. It is distinguished from components *within* the boundary by the fact that it is independently owned, operated, or authorized — and therefore not directly governed by the controls of the system it connects to — while still being relevant to that system's risk posture, data flows, and scope determinations. In practice, security frameworks use the expression to delineate where one system's security responsibility ends and another's begins: an authorization boundary covers 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. For each interconnection between systems owned or operated by different organizations, frameworks require documentation of the authorization for the connection and the sharing of information. An authorization boundary provides a diagrammatic illustration of a provider's internal services, components, and other devices along with connections to ex
Source
within the system and between connected systems.the sentence this term was read in
generalized from a web lookup of the quoted expression at proposal time Verdict: compositional.
- Official websites use .gov
- NIST Special Publication 800-18 Revision 1 Guide for Developing Security
- CSP A FedRAMP Authorization Boundary Guidance
- Data Flow Diagrams
A definition generalized from search results is a draft to react to, not provenance. Confirm it against an authority document before this term is verified.
A web lookup ran when this term was proposed
A neighboring or peer information system that shares data flows, communications links, or control relationships with a given system under evaluation, placing it outside that system's authorization boundary while remaining relevant to its security posture. Its distinguishing feature is the cross-boundary relationship: the connected system is not merely a component within the system being assessed, but an external entity whose interactions must be governed, documented, and controlled — for example through interconnection security agreements, flow-enforcement mechanisms, or boundary protection devices. NIST SP 800-171r3 uses the concept to frame rules such as prohibiting CUI transfers between interconnected systems and controlling information flows "within systems and between interconnected systems." NIST SP 800-18r2 similarly treats a system's authorization boundary and its interconnected systems as the combined scope that security and privacy plans must address. Across frameworks, the phrase is applied wherever planners must trace risks, data flows, and control responsibilities that cross from one independently governed system to another.
Advisory only. A term this product ships is defined by an authority document, not by a search result.
Proposed during multiword review of this document in the CKI mapping queue.
Attested in
Classifications
Entity Type
Sensitivity
Information Class
Variants
- plural
- connected systems
- possessive
- connected system's
- pluralpossessive
- connected systems'
Framework definitions
- §1 · attested_usage_reviewer_confirmed
- No definition is given in NIST SP 800-171r3. The term is attested in use at 1 citation in that document; a definition is pending curation.Increment 2: attested in 800-171r3 without a glossary definition.
- §1 · web_lookup_draft
- Any information system, application, or infrastructure component that lies **outside** a given system's authorization boundary yet maintains a data-flow, network, or processing link to it. It is distinguished from components *within* the boundary by the fact that it is independently owned, operated, or authorized — and therefore not directly governed by the controls of the system it connects to — while still being relevant to that system's risk posture, data flows, and scope determinations. In practice, security frameworks use the expression to delineate where one system's security responsibility ends and another's begins: an authorization boundary covers 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. For each interconnection between systems owned or operated by different organizations, frameworks require documentation of the authorization for the connection and the sharing of information. An authorization boundary provides a diagrammatic illustration of a provider's internal services, components, and other devices along with connections to exDR-088 backfill from the noun definition column