DISCUSSION [NIST SP 800-171 R2]

Separation of duties addresses the potential for abuse of authorized privileges and helps to reduce the risk of malevolent activity without collusion. Separation of duties includes dividing mission functions and system support functions among different individuals or roles; conducting system support functions with different individuals (e.g., configuration management, quality assurance and testing, system management, programming, and network security); and ensuring that security personnel administering access control functions do not also administer audit functions. Because separation of duty violations can span systems and application domains, organizations consider the entirety of organizational systems and system components when developing policy on separation of duties.

Further Discussion

No one person should be in charge of an entire critical task from beginning to end. Documenting and dividing elements of important duties and tasks between employees reduces intentional or unintentional execution of malicious activities.

Example 1

You are responsible for the management of several key systems within your organization. You assign the task of reviewing the system logs to two different people. This way, no one person is solely responsible for the execution of this critical security function [c].

Example 2

You are a system administrator. Human Resources notifies you of a new hire, and you create an account with general privileges, but you are not allowed to grant access to systems that contain CUI [a,b]. The program manager contacts the team in your organization that has system administration authority over the CUI systems and informs them which CUI the new hire will need to access. Subsequently, a second system administrator grants access privileges to the new hire [c].

Potential Considerations

Does system documentation identify the system functions or processes that require separation of duties (e.g., function combinations that represent a conflict of interest or an over-allocation of security privilege for one individual) [a]?

Copyright

Copyright 2020, 2021 Carnegie Mellon University and The Johns Hopkins University Applied Physics Laboratory LLC.

Copyright 2021 Futures, Inc.

This material is based upon work funded and supported by the Department of Defense under Contract No. FA8702-15-D-0002 with Carnegie Mellon University for the operation of the Software Engineering Institute, a federally funded research and development center, and under Contract No. HQ0034-13-D-0003 and Contract No. N00024-13-D-6400 with the Johns Hopkins University Applied Physics Laboratory LLC, a University Affiliated Research Center.

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