Time to step up: Actions you can take today
Your control system cyber assets were not coded with security in mind, so you have to build defenses yourself, always thinking about your complete security posture. Here are ways to start now.
Control systems represent a high-value target and are under attack. How bad is the risk? A recent survey and webcast conducted by Control Engineering indicated that most respondents recognize that the risk is high to severe. What really is the risk? The ancient risk calculation method tries to associate the threat with the vulnerability. It requires both the actual asset vulnerability combined with a threat actor motivated to exploit that vulnerability. Increasing international tensions have increased the motivation of threat actors worldwide. A recent vendor briefing highlighted how vulnerable industrial cyber assets and their communications protocols truly are. The vulnerabilities transcend product lines within vendors and across vendors. The situation is improving in some areas, but most industrial control system (ICS) product suppliers and integrators do not have a security process within their software development and system integration lifecycle, or are early in their efforts. Security cannot be an afterthought and requires foundational controls.
So if you know that there is risk, what can you do? You could rip and replace immediately, but you may find your new solution is just as vulnerable as the old. You have to know what you have, build walls, monitor, and respond to threat indicators. Are your people trained to do those?
Step one, which you can begin today, is create an inventory of your control system assets. This includes all personnel and skills, controller hardware, networking hardware, communication channels, and operational procedures. Step two, take a look into any regulations impacting your cyber, physical, and operational security requirements. If you do not have any (yet), then consider yourself lucky; it will be up to you to justify a cash outlay for security to your management. However, if you are in the energy or water sectors, several cyber security controls are already impacting you or will be soon.
Once you compile your initial inventories, the next steps are:
1. Create a baseline of security needs throughout your organization and its stakeholders. This is a key ingredient, as your organization will most likely have to create new roles and responsibilities to address ongoing threats.
2. Using your inventory of cyber assets, identify which are required for direct control functions. Then, identify what communication channels, applications, and services are required for each ICS cyber asset to perform its operations. This process will not be easy, and your control system vendors and integrators may not have specific answers for your environment. This process proves a reason to stand up a test environment.
3. Remove all other communication channels, applications, and services not necessary for normal and emergency operating conditions.
4. Review the remaining communication channels, applications, and services for vulnerabilities. Using the inventory of firmware, applications, and protocol versions, check them for out-of-date and/or vulnerable cyber asset components.
5. Identify mitigating controls such as a network intrusion detection system (IDS). The IDS should be configured with specific rule sets for your control system protocols and communication channels, and not generic rules for traditional IT environments.
6. Inventory your current operational procedures used by personnel to maintain the cyber assets and communication channels used for control system operations. Review the procedures for vulnerabilities, and modify them as necessary.
This is only a start to the process of addressing the security needs of today’s control system environments. The risk is real. I can show you firsthand many ways that control system hardware, firmware, logic, and communication protocols are highly vulnerable to cyber attack. Building defenses does not have to be complicated, but it must be methodical. There are proven IT defensive techniques that can protect vulnerable ICS devices, but often those ICS devices are still vulnerable because many vendors do not have a security process within their software development lifecycle.
Therefore, the first step is for you, the asset owner and operator, to learn about what you have, what you need, and how to protect your networks with walls and limited trusts. It is also up to you to request a cyber, physical, and operational vulnerability assessment for all new implementations, including how any new device is coupled to your existing infrastructure. It is then up to you as the asset owner and operator to take the necessary precautions to limit and monitor physical, cyber, and operational interactions with your control environment. For example, a laptop used by a technician should not be categorized as a tool. A laptop is very different from a hammer, and the intended use of the device may become compromised if not properly handled. Therefore, a laptop must be monitored differently than any other tool. This ideology has to transcend all aspects of your ICS environment. The cultural change and new responsibilities required are necessary but will not be an easy shift.
Matt Luallen is founder of Cybati, a security training and consulting organization.