FedRAMP Controls / AC

AC-20 Use of External Systems

Family AC
Baselines moderate
Mapped KSIs 3

Control statement

a.  {{ insert: param, ac-20_odp.01 }} , consistent with the trust relationships established with other organizations owning, operating, and/or maintaining external systems, allowing authorized individuals to:
        1. Access the system from external systems; and
        2. Process, store, or transmit organization-controlled information using external systems; or
    b. Prohibit the use of {{ insert: param, ac-20_odp.04 }}.
        Guidance: The interrelated controls of AC-20, CA-3, and SA-9 should be differentiated as follows:

AC-20 describes system access to and from external systems.

CA-3 describes documentation of an agreement between the respective system owners when data is exchanged between the CSO and an external system.

SA-9 describes the responsibilities of external system owners. These responsibilities would typically be captured in the agreement required by CA-3.

Parameter placeholders {{ insert: param, … }} reference FedRAMP-set values in the resolved profile. Full parameter map is preserved in the catalog database.

Covered by these Key Security Indicators

KSITitleCategory
KSI-IAM-05Least Privilege
_Persistently_ ensure that identity and access management employs measures to ensure each user or device can only access the resources they need.
Identity and Access Management
KSI-TPR-03Supply Chain Risk Management
_Persistently_ identify, review, and mitigate potential supply chain risks.
Third-Party Information Resources
KSI-TPR-04Supply Chain Risk Monitoring
Automatically monitor third party software _information resources_ for upstream vulnerabilities using mechanisms that may include contractual notification requirements or active monitoring services.
Third-Party Information Resources