In the present world, every device is smart and controllable through the Internet. Therefore, companies spend a lot of money on ensuring the network security of embedded devices. But embedded devices are still vulnerable to attacks from different sources. Have you wondered why and how? 

The answer is simple. Network security is not enough for embedded devices. In embedded devices, there are many other types of attacks such as Physical attacks, malicious software injections, cloud attacks, operating system vulnerability violations, and memory attacks. Therefore, we should address every possible attack in embedded systems and take proper action to reduce the attack surface. 

In this article, we will have a brief look at different types of attacks on embedded devices and possible measures to reduce the attack surfaces. So, let’s get started!

Common Attacks on Embedded Devices: 

Let us discuss a few common attacks on embedded devices! 

1. Network Attacks: 

Network attacks are of course most common in embedded devices. Network attacks range from failing the braking system of vehicles that can cost your life to getting the secret data of the users that can be used against them in the future. Hackers can break networks using multiple types of attacks like phishing, Distributed Denial of Service (DDOS), Man-in-the-Middle (MitM) Attacks, Malware injections and spoofing etc.

2. Physical Attacks: 

The most underestimated security measure in embedded systems is physical security. Most companies don’t pay attention to physical security and often face a huge threat from this endpoint. Hackers can mischievously access embedded devices physically and upload malicious firmware through serial interfaces available for programming and debugging, if left opened. Besides, they can also desolder drives and memory components and steal secret data and even firmware from there. 

3. Software Integrity: 

Can you confidently say your device is running only the firmware you programmed? Have you taken steps to verify and protect its integrity? Skipping these measures is a common oversight that can have serious consequences. If you don’t ensure software integrity, your device can run any software without authentication. Imagine if someone physically violates your device to run malicious firmware or hacks your update process and changes the firmware midway, your device will never know that it’s malicious code and will run it anyway. 

4. Software Security: 

Software security refers to the phenomenon that your software can detect any strange activity in the system during critical operations and send proper warnings in case of anonymous activities. Software security is very critical in features like user authentication, input validation and critical data handling of the system. The worst part is that buffer overflow and improper memory management can also put software at risk. Threat actors can attack the system’s memory causing it to crash if the memories are not well managed in firmware. 

Ensure Embedded Security in Embedded Systems: 

Now we will discuss the different ways to ensure embedded security in the embedded systems. 

1. Physical Security: 

Physical security starts by selecting the appropriate chip or microcontroller for your device and then it expands to PCB design and even firmware also. Physical security limits the access to sensitive data using different SOC features like immutable memory, e-fuses to store bootloader keys, tamper-resistant storage, and security enclaves to store sensitive code. Similarly, in PCB design, you should never keep the JTAG, debugging UARTs and factory reset options open. Otherwise, someone can play with them easily and manipulate your device.  

2. Network Attacks: 

To minimize the risk of network attacks in the embedded systems, all of the irrelevant and unused network ports must be closed in releases. Use standard and strong encryption protocols for sharing data with cloud and other networks. It will reduce the sniffing and Man-in-the-middle attacks.  All OTA firmware updates and certificates over network must be encrypted. Implementing proper login and authentication management is also necessary to reduce the attacks on networks such as session hijacking. 

3. Software Integrity: 

To ensure that only trusted firmware signed by software vendors or OEM is running on your embedded systems, Secure Boot is used. It is a technique that allows only signed and trusted and authorized software to run on embedded systems. The Secure Boot starts its magic when the user presses the start button. It checks the authenticity of the first stage boot component using keys stored in e-fuses. This is called Root of trust. Then the first stage component verifies the signature of second stage boot component and the chain goes on to loading kernel and finally root filesystem. In this way, no one can run malicious code on embedded hardware as every boot component verifies the signature of the next component. 

4. Software Security: 

Bad software practices and poor memory management can lead to many attacks on embedded systems as we have already discussed above. Therefore, you should always use safe language for your embedded firmware. To prevent buffer overflow, creating a sandbox is a good solution as it isolates flowing data from the system. However, the best practice is that we should create a memory management unit that should only allocate a sufficient number of buffers for the operating system and applications. Good memory management unit maintains the balance of embedded systems operations and buffer overflow attacks. 

Secure Your Embedded Devices Now! 

Developing secure and reliable firmware for embedded systems is a quite complex task. It requires proper planning about network protocols, physical and network ports, memory management, encryption schemes, software standards and OTA releases to maintain a reliable and secure firmware for embedded systems. 

EPTeck has been providing its expertise in ensuring embedded systems for many years and has implemented complete embedded security solutions for many tech giants in Europe. 

If you need any consultation about security in your embedded system, book a free consultation now!