Control statement
- a.Authorize internal connections of [Organization-defined: system components] to the system;
- b.Document, for each internal connection, the interface characteristics, security and privacy requirements, and the nature of the information communicated;
- c.Terminate internal system connections after [Organization-defined: conditions] ; and
- d.Review [Organization-defined: frequency] the continued need for each internal connection.
Discussion
Internal system connections are connections between organizational systems and separate constituent system components (i.e., connections between components that are part of the same system) including components used for system development. Intra-system connections include connections with mobile devices, notebook and desktop computers, tablets, printers, copiers, facsimile machines, scanners, sensors, and servers. Instead of authorizing each internal system connection individually, organizations can authorize internal connections for a class of system components with common characteristics and/or configurations, including printers, scanners, and copiers with a specified processing, transmission, and storage capability or smart phones and tablets with a specific baseline configuration. The continued need for an internal system connection is reviewed from the perspective of whether it provides support for organizational missions or business functions.
Organization-defined parameters
These values must be resolved through the organization’s tailoring and governance process. Bracketed parameter references in the control text identify where a decision is required.
From control text to operational evidence
Use Internal System Connections as a testable risk decision. Translate the official statement into accountable people, repeatable processes, configured technology, and evidence that demonstrates the outcome over time. In this family, pay particular attention to assessment independence, authorization evidence, remediation, and continuous monitoring.
Implementation workflow
- Define the control boundary, responsible owner, inherited portions, and systems or processes in scope.
- Resolve each organization-defined parameter before declaring the control implemented.
- Document how the implementation satisfies every clause of the official control statement.
- Collect evidence as a normal byproduct of operation rather than only before an assessment.
- Review exceptions, changes, and monitoring results on a risk-based cadence.
Evidence examples
- assessment plans and reports
- plans of action and milestones
- authorization decisions and risk acceptances
- continuous monitoring results
Common failure patterns
- control status based only on owner assertion
- findings closed without evidence
- assessment scope that misses inherited services
- monitoring data disconnected from authorization decisions
Questions practitioners should ask
- What risk decision is this control intended to support in this system?
- Which parts are implemented locally, inherited, shared, or not applicable—and what evidence supports that decision?
- Do the documented narrative, deployed configuration, operating process, and collected evidence agree?
- What event or threshold requires the implementation to be reviewed or changed?
Assessment objectives and methods
Show the assessment objective
- CA-09a.internal connections of [Organization-defined: system components] to the system are authorized;
- CA-09b.
- CA-09b.[01]for each internal connection, the interface characteristics are documented;
- CA-09b.[02]for each internal connection, the security requirements are documented;
- CA-09b.[03]for each internal connection, the privacy requirements are documented;
- CA-09b.[04]for each internal connection, the nature of the information communicated is documented;
- CA-09c.internal system connections are terminated after [Organization-defined: conditions];
- CA-09d.the continued need for each internal connection is reviewed [Organization-defined: frequency].
Examine
- Assessment, authorization, and monitoring policy
- access control policy
- procedures addressing system connections
- system and communications protection policy
- system design documentation
- system configuration settings and associated documentation
- list of components or classes of components authorized as internal system connections
- assessment report
- system audit records
- system security plan
- privacy plan
- other relevant documents or records
Interview
- Organizational personnel with responsibilities for developing, implementing, or authorizing internal system connections
- organizational personnel with information security and privacy responsibilities
Test
- Mechanisms supporting internal system connections
Related controls
These relationships come from the official OSCAL catalog. They indicate useful dependencies or context, not automatic inheritance or equivalence.
Control enhancements
Enhancements add specificity, strength, or scope to the base control. Baseline badges show explicit selections in the official SP 800-53B OSCAL profiles.
CA-9(1) — Compliance Checks
Perform security and privacy compliance checks on constituent system components prior to the establishment of the internal connection.
Official discussion
Compliance checks include verification of the relevant baseline configuration.
Assessment objectives and methods
- CA-09(01)[01]security compliance checks are performed on constituent system components prior to the establishment of the internal connection;
- CA-09(01)[02]privacy compliance checks are performed on constituent system components prior to the establishment of the internal connection.
Examine
- Assessment, authorization, and monitoring policy
- access control policy
- procedures addressing system connections
- system and communications protection policy
- system design documentation
- system configuration settings and associated documentation
- list of components or classes of components authorized as internal system connections
- assessment report
- system audit records
- system security plan
- privacy plan
- other relevant documents or records
Interview
- Organizational personnel with responsibilities for developing, implementing, or authorizing internal system connections
- organizational personnel with information security and privacy responsibilities
Test
- Mechanisms supporting compliance checks
Related controls
Authoritative sources
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. Official control requirements and interpretations remain with NIST and the responsible authorizing organization.