Embedded Systems – CompTIA Security+ SY0-501 – 3.5

| December 12, 2017


We use embedded operating systems every day, but we don’t always consider the underlying operation and complexities of these embedded technologies. In this video, you’ll learn about the security concerns associated with many different embedded systems.

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SCADA stands for Supervisory Control and Data Acquisition System. You may also see this referred to as Industrial Control Systems, or ICS. SCADA systems are large pieces of equipment, usually used in manufacturing or in power distribution. And we need some way to connect all of these devices together so that you can control them from one central location. And that’s when we find a SCADA network.

It’s a distributed control system. There’s real-time access to all of these systems. And it allows for centralized control of all of these very large industrial systems. When you’re talking about a SCADA system that manages our power infrastructure, there are some significant national security concerns.

And that’s why most of the time you’ll see all of these SCADA systems around their own private segmented network. Normally there’s no access to a SCADA network if you’re on the internet or somewhere outside of that immediate network. There’s usually tight controls and a lot of security to keep people away from these SCADA networks.

We’ve seen an increase in the number of available smart devices that you can wear. These wearable technologies might be smartwatches or health monitors. Since these devices are connected to you, some of these devices will track exactly where you happen to be during the day, the real question you might have from a security perspective is where is that information stored, and who has access to all of that information?

We have similar concerns with what we call the Internet of Things, that is, home automation devices that we are connecting now to the internet. We have video doorbells, garage door openers, our heating and cooling systems, and almost everything in our home is becoming connected to the internet. These Internet of Things devices know when we’re home, they know when we’re not home. And if somebody does gain access to those systems, they potentially can gain access to your entire house.

If somebody calls you with a question about the HVAC system, they’re referring to the heating, ventilation, and air conditioning system. These are usually very large and very complex systems that are installed in large enterprises. The HVAC infrastructure that’s put into these large installations is not something that can be easily designed. Normally you need an expert in thermodynamics in HVAC systems to be able to properly design and implement such a system.

These HVAC systems aren’t just standalone units, they’re integrated with other components in the infrastructure. For example, it’s common to network an HVAC system with the fire alarm system. That way if a fire alarm does go off, the HVAC system will not provide additional oxygen to help feed the fire. You can limit the impact of a fire just by integrating those systems together.

There is usually a centralized PC or system that manages all of these HVAC units. This is not something that people commonly think about from a security perspective. But if someone did want to create a Denial of Service situation, they simply need to turn off the air conditioning or turn off the heating and make the temperature in the building so uncomfortable that no one would be able to stay and work.

One popular embedded system these days is the System on a Chip, or the SoC. A System on a Chip is one where most of the activities for that particular system take place inside of a single piece of silicon. There is usually supporting devices around that chip, but the chip is really handling the main focus of the processing.

These SoC devices are usually a very small form factor. Take for example this Raspberry Pi 2. This Broadcom chip in the middle is the System on a Chip.

Everything else on this particular device is an interface that gets you to the network USB interfaces, or an HDMI video interface. When all of the major components are collapsed down into a single chip, it becomes difficult to provide any type of security patches. If you do need to upgrade or change this component, it usually means that you will be replacing the entire piece of hardware.

Here’s a close up view of a System on a Chip. This is the Raspberry Pi 3. You can see this Broadcom BCM 2837 is the System on a Chip that is really controlling everything about this Raspberry Pi. The only other major component you see on this device is this additional controller unit for the USB and the ethernet interfaces. Everything else on this particular device is all done inside the System on a Chip.

A Real-Time Operating System, or RTOS, is an operating system where the processes running are deterministic. That means there are certain processes in this operating system that are guaranteed to be processed in a particular amount of time. We often see a Real-Time operating system used on devices like industrial equipment and automobiles.

A good example of this is when you need to break very quickly to avoid something in the road, you don’t want to have the processing system of your car have to wait on another process to finish before it will begin hitting your anti-lock brakes. For example, if you hit the anti-lock brakes in your car, you would like those brakes to engage immediately. You don’t want some other process occurring in the card to take priority over those breaks. The Real-Time operating system ensures that those breaks will always be available the instant you press them.

These are Real-Time operating systems are usually managing a relatively important process. These are nontrivial systems that always need to be available. And that’s why security is so important with a Real-Time operating system, you don’t want something to embed itself in the system and prevent one of those Real-Time processes from being able to engage.

These days we’ll often find connected to our networks these devices called multifunction devices, or MFDs. These are devices that aren’t just a printer, they’re also providing scanning and faxing capabilities all in one single unit. Because of the complexities involved in being able to manage all of these different types of services, the firmware and operating system that’s running in these devices is relatively sophisticated. But these devices can also be security concerns.

For example, if someone scans information on one of these multifunction devices, the image is often saved locally in the memory of that device. That means somebody who does want to retrieve that image could access that machine and potentially gain information that they normally would not have access to. The same could be said for the faxes that are sent from this device, since most of these devices will initially scan the pages before sending them out as fax images.

Those surveillance cameras that we use are also embedded systems. These are the cameras that we use for video monitoring and security surveillance. In most cases, these cameras are connecting back to a central video recorder, and very often, we’re able to access that video recorder using an application and communicating to it via TCP/IP.

Not only is the recorder an IP addressable device, these days, the cameras themselves communicate via TCP/IP. So if someone was able to gain access to these IP connected systems, they would also be able to surveil your property and know exactly when you were home, when you were not home, and knew exactly what type of security you would have in place at your facility. We often see embedded systems used for medical purposes, things like heart monitors and insulin pumps. And even if we don’t have direct access to the operating system in these devices, there’s still a security concern, especially given the importance of these medical devices.

There are more and more embedded systems being added to our vehicles as well. Our cars and our trucks now have systems that can be accessed external from the car, allowing someone with the right type of access to not only be able to see what’s happening with that car, but to be able to control the components inside the vehicle, as well. Some security proof of concepts have even found that it’s possible to control and disengage the engine in these devices, all from someone who’s located far away from the actual car.

And there’s also embedded systems inside of these flying devices, these aircrafts and UAVs, these Unmanned Aerial Vehicles. These UAVs and the cameras attached to them provide some amazing pictures from the sky. But if someone does perform a Denial of Service to this device, it’s one that could fall out of the sky and potentially be a danger to the people on the ground.

Category: CompTIA Security+ SY0-501

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