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Security Control Spotlight: AC-20 (Use of External Information Systems)

By Ernest Smith, CISSP, PMP

Requirement (simplified):
Do you have contracts and or service level agreements with the owners of any system outside of your authorization boundary that are processing, storing, and transmitting your information?
Breakdown:
What is an “external information system”?

  • Employee personally owned devices (I said it!)
  • Systems controlled by nongovernmental organizations
  • Government organization system who has an ATO signed by an AO other than yours
  • Cloud service offerings

Questions:

  • Is any of your information being processed, stored and transmitted by any of the above? How do authorized users access your information from this external information system?
  • If yes, do you have a contract in place that outlines how your system’s information will be protected from unauthorized disclosure, etc.? How detailed is that contract?
  • If yes, do these systems have an ATO? Do you have a copy of that ATO?
  • Are you using Office 365, Google Business, or other cloud service offering? Do you have a document where the DoD has issued that service a provisional authorization (ATO), or at least FedRamp ATO’d?

Issues:
How close are you watching your employees? What are the possibilities they have your information on their privately-owned devices? How would you know? Remember to follow your data everywhere it goes once it leaves your authorization boundary!


Post Categories: Risk Management Framework Tags:  CONTROLS NIST SP 800-53 RMF