Cyber Resilience

NIST 800-53 r5 · Controls catalogue · Family CA

CA-9Internal System Connections

Authorize internal connections of {{ insert: param, ca-09_odp.01 }} to the system; Document, for each internal connection, the interface characteristics, security and privacy requirements, and the nature of the information communicated; Terminate internal system connections after {{ insert: param, ca-09_odp.02 }} ; and Review {{ insert: param, ca-09_odp.03 }} the continued need for each internal connection.

Last updated: 22 August 2026 07:11 UTC

Implementations targeting this control (0)

ATT&CK techniques this control mitigates (0)

Weaknesses this control addresses (10)AI-assisted

CWEs ranked by how often they appear in real CVEs. The rationale describes how this control reduces exploitability of each weakness class.

CWE Name CVEs Why this control addresses it
CWE-862Missing Authorization10,200+Requiring explicit authorization for each internal connection prevents missing authorization.
CWE-284Improper Access Control6,900+Authorizing and reviewing internal connections enforces proper access control over system interfaces.
CWE-863Incorrect Authorization3,900+Periodic review and documentation of connection needs reduces incorrect authorization.
CWE-269Improper Privilege Management3,400+Terminating and reviewing connections manages privileges associated with internal interfaces.
CWE-285Improper Authorization1,500+Documenting security requirements and authorizing connections ensures correct authorization decisions.
CWE-668Exposure of Resource to Wrong Sphere800+Controlling internal connections prevents exposure of resources to unintended internal spheres.
CWE-250Execution with Unnecessary Privileges300+Automatic termination after a defined period eliminates unnecessary privileges from persistent connections.
CWE-1220Insufficient Granularity of Access Control100+Documenting interface characteristics enables more granular control over internal access.
CWE-653Improper Isolation or Compartmentalization73Reviewing the continued need for connections supports isolation and compartmentalization.
CWE-501Trust Boundary Violation33Authorizing and reviewing connections helps maintain proper trust boundaries between internal components.

Top CVEs where this control is the strongest mitigation

CVE Risk CVSS EPSS Match
No CVEs annotated to this control yet — the per-CVE backfill is in progress.

Other controls in family CA

CA-1 CA-2 CA-3 CA-4 CA-5 CA-6 CA-7 CA-8