Emerson Exchange 365

Cyber security starts at the communications links to devices. On Emerson PLC/PAC control products, support for non-essential ports and protocols is removed. Station Manager, USB and SD card ports are disabled by default. Access to the devices is restricted to only what is needed for the supported communications protocols: HTTP Proxy support for controlled access to the Internet, and HTTPS protocols with certificates for secure Predix connection on the WAN. We have even implemented a private cellular network with carriers for our Field Agent products. Emerson reduces the attack surface of its PLC/PAC products by limiting access to essential ports and services. Emerson also acquires cyber security certification for our control products. Whether it is the globally recognized Achilles Level 2 certification, or the specific TRIMPS certification, these designations indicate that Emerson PLC/PAC control systems meet global security standards.

Achilles Testing
The Wurldtech Achilles certifications are communications tests performed on devices while monitoring specific performance indicators. Achilles testing is categorized into three main groups:

• Achilles Grammar – Achilles Grammar tests for protocol boundary conditions in the device communications. They systematically iterate over each field and combinations of fields to produce repeatable, quantifiable tests of the common types of implementation errors. Achilles Grammar tests send invalid, malformed, or unexpected packets to the Device Under Test (DUT) to test for vulnerabilities in specific layers of the protocol stack.
• Achilles Storms – Achilles Storms generate packets at a high rate to examine the DUT’s ability to handle high traffic rates for different protocols. The Achilles Test Platform also includes the ability to search for the denial-of-service threshold for a given type of storm traffic – the storm rate at which the device can no longer respond to other normal requests.
• Known Vulnerabilities – Known vulnerability test cases generate exploit traffic for vulnerabilities that have a high probability of existing in control devices. Wurldtech further describes the Achilles Grammar tests as a “fuzz test” where invalid, unexpected, or random data is provided to the inputs. The program is then monitored for exceptions such as crashes, or failing built-in code assertions, or for finding potential memory leaks. While conducting Achilles testing, the equipment is monitored using communications responses, discrete and analog signals. The device must maintain the responses and signals within acceptable specifications throughout the test.

Emerson encourages customers to use enhanced communication protocols. OPC UA is widely accepted for its secure communications between systems. OPC UA is platform-independent and no longer requires security of COM/DCOM. OPC UA security allows for managed certificate exchange between client and server. This certificate is an electronic ID held by the application that defines the identity of the holder. These certificates conform to the X509 specification. The data is encrypted between end points of the OPC UA exchange to deny man-in-the middle access. Even with its enhanced features, OPC UA is IT network friendly and communicates through standard HTTP or UA TCP port. OPC UA can even connect securely over VPN and through firewalls.

Reducing attack surface is only a piece of the security puzzle. Check out other blogs in this Forum for additional tips on securing your PLC/PAC control systems.