CA-3_information-exchange

CA-3 Information Exchange

High-Level Description

Family: Assessment, Authorization, and Monitoring (CA) Framework: NIST SP 800-53 Rev 5

System information exchange requirements apply to information exchanges between two or more systems. System information exchanges include connections via leased lines or virtual private networks, connections to internet service providers, database sharing or exchanges of database transaction information, connections and exchanges with cloud services, exchanges via web-based services, or exchanges of files via file transfer protocols, network protocols (e.g., IPv4, IPv6), email, or other organization-to-organization communications. Organizations consider the risk related to new or increased threats that may be introduced when systems exchange information with other systems that may have different security and privacy requirements and controls. This includes systems within the same organization and systems that are external to the organization. A joint authorization of the systems exchanging information, as described in CA-6(1) or CA-6(2) , may help to communicate and reduce risk.

Authorizing officials determine the risk associated with system information exchange and the controls needed for appropriate risk mitigation. The types of agreements selected are based on factors such as the impact level of the information being exchanged, the relationship between the organizations exchanging information (e.g., government to government, government to business, business to business, government or business to service provider, government or business to individual), or the level of access to the organizational system by users of the other system. If systems that exchange information have the same authorizing official, organizations need not develop agreements. Instead, the interface characteristics between the systems (e.g., how the information is being exchanged. how the information is protected) are described in the respective security and privacy plans. If the systems that exchange information have different authorizing officials within the same organization, the organizations can develop agreements or provide the same information that would be provided in the appropriate agreement type from CA-3a in the respective security and privacy plans for the systems. Organizations may incorporate agreement information into formal contracts, especially for information exchanges established between federal agencies and nonfederal organizations (including service providers, contractors, system developers, and system integrators). Risk considerations include systems that share the same networks.

What to Check

• Verify CA-3 Information Exchange is documented in SSP
• Validate all 3 control requirements are implemented
• Confirm control is operating effectively
• Review evidence of continuous monitoring for CA-3

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for CA-3 implementation details. Verify the organization has documented how this control is satisfied.

Step 2: Validate Implementation

# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null

Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

Tools

Remediation Guide

Control Statement

Approve and manage the exchange of information between the system and other systems using [organization-defined]; Document, as part of each exchange agreement, the interface characteristics, security and privacy requirements, controls, and responsibilities for each system, and the impact level of the information communicated; and Review and update the agreements [organization-defined].

Implementation Guidance

System information exchange requirements apply to information exchanges between two or more systems. System information exchanges include connections via leased lines or virtual private networks, connections to internet service providers, database sharing or exchanges of database transaction information, connections and exchanges with cloud services, exchanges via web-based services, or exchanges of files via file transfer protocols, network protocols (e.g., IPv4, IPv6), email, or other organization-to-organization communications. Organizations consider the risk related to new or increased threats that may be introduced when systems exchange information with other systems that may have different security and privacy requirements and controls. This includes systems within the same organization and systems that are external to the organization. A joint authorization of the systems exchanging information, as described in CA-6(1) or CA-6(2) , may help to communicate and reduce risk.

Authorizing officials determine the risk associated with system information exchange and the controls needed for appropriate risk mitigation. The types of agreements selected are based on factors such as the impact level of the information being exchanged, the relationship between the organizations exchanging information (e.g., government to government, government to business, business to business, government or business to service provider, government or business to individual), or the level of access to the organizational system by users of the other system. If systems that exchange information have the same authorizing official, organizations need not develop agreements. Instead, the interface characteristics between the systems (e.g., how the information is being exchanged. how the information is protected) are described in the respective security and privacy plans. If the systems that exchange information have different authorizing officials within the same organization, the organizations can develop agreements or provide the same information that would be provided in the appropriate agreement type from CA-3a in the respective security and privacy plans for the systems. Organizations may incorporate agreement information into formal contracts, especially for information exchanges established between federal agencies and nonfederal organizations (including service providers, contractors, system developers, and system integrators). Risk considerations include systems that share the same networks.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - CA-3
• NIST SP 800-53A Rev 5 (Assessment Procedures)
• NIST SP 800-53 Rev 5 Full Catalog

Checklist

• Control documented in SSP
• Implementation evidence collected
• Operating effectiveness validated
• Continuous monitoring in place
• Related controls (AC-4, AC-20, AU-16, CA-6, IA-3) reviewed