Use of an SDN Switch in Support of NIST ICS Security Recommendations and Least Privilege Networking

If an attacker is able to successfully subvert a device within a network, that often gives them easier access to spread the intrusion to other devices in the network. Common guidance, such as that provided in NIST SP 800-82, recommends network separation and segregation to enforce least privilege within a network, to act as a mitigation against such attacks. This paper evaluates the use of SDN network switches to implement least privilege networking within an industrial control system, and maps SDN switch capabilities to NIST 800-82 recommendations and the corresponding NIST 800-53 security controls. This paper also reports on experiments conducted with two SDN switches to validate the effectiveness of the switches in support of these mappings. Our findings indicate that with appropriate planning, several aspects of least privilege networking, and several of the NIST controls can be implemented with an SDN switch. However, poor configurations can still result in insecure systems.