Introduction: Recent attacks on communication devices like pagers have raised serious concerns among users of electronic devices worldwide. It serves as a wake-up call to perform thorough hardware validation to ensure the integrity of the electronic devices. Beyond confidentiality, it has become a question of confidence to trust a device. While cybersecurity has been the focus of software until now, it is now quite evident that hardware cyber security must be focused on and is inevitable. Hardware penetration testing shall soon become a mandatory stage in the secure SDLC, which may contain a wide range of testing such as validating a device against Side Channel Attacks (SCA), Fault Injection Attacks, etc.
Moreover, it shall not be a straightforward way of verification as this validation not only requires huge investment for setting up the pen testing lab but even after certifying the hardware, there are potential chances that the hardware can be manipulated through both invasive and passive methods during the supply chain process. This blog aims to raise awareness of the importance of including hardware penetration testing in all products that use semiconductor electronic devices. This ranges from basic ECUs or MCUs in modern vehicles to healthcare devices and IoT products. To stay focused, the below blog shall focus on Side Channel Attack and Fault Injection Attacks.
Understanding Side Channel Attacks (SCA):
Let’s understand SCA from an Automotive scenario. Consider an Automotive Electronic Control Unit (ECU – for the same of simplicity imagine ECU as a feature rich extended version of an Integrated Chip) responsible for controlling the vehicle’s headlight system as an example. There may be multiple ECUs in a vehicle but the functionality of this ECU is to detect vehicles coming in the opposite direction using sensors and automatically switches the headlights from high beam to low beam to prevent blinding other drivers. Such an ECU processes sensor data in real-time and makes critical decisions, making it a valuable target for attackers using Side Channel Attacks (SCAs).
In this scenario, the ECU gathers data from sensors such as cameras or light sensors to detect the presence of an oncoming vehicle. Once detected, it triggers a change in the headlight settings. During these operations, the ECU performs computations and potentially uses encryption to communicate securely with other systems in the vehicle, which could emit side-channel signals.
Here’s how a Side Channel Attack could target this ECU:
1. Monitoring Phase:
The attacker begins by monitoring the ECU’s physical signals (through Physical Access to the ECU or Direct Circuitry Access) while it processes sensor data and makes adjustments to the headlight system. For example, as the ECU decides to switch from high beam to low beam when detecting an oncoming vehicle, the attacker can measure the ECU’s power consumption or electromagnetic emissions during this operation. This monitoring can occur without physical contact with the ECU.
2. Data Collection:
Over time, the attacker collects enough data to capture patterns in how the ECU behaves when it detects an oncoming vehicle and adjusts the headlight settings. For example, during each switch from high beam to low beam, the ECU’s power usage might fluctuate in a recognizable way, revealing patterns in the decision-making process.
3. Data Analysis:
After collecting sufficient data, the attacker analyses the information to extract patterns related to the ECU’s operations. The fluctuations in power consumption or timing information might reveal how the ECU processes sensor inputs or how it triggers the headlight switch. If the ECU uses encryption to communicate with other vehicle systems, the attacker may also be able to infer cryptographic keys or other sensitive data from the side-channel signals.
4. Exploitation:
With this information, the attacker could potentially manipulate the ECU’s behaviour. For instance, they might inject false signals that cause the ECU to malfunction, preventing it from switching to a low beam when an oncoming vehicle is detected, or they could alter the system’s timing to cause improper headlight adjustments. Such an attack could reduce driver safety by leaving the high beam on and dazzling the drivers of oncoming vehicles, leading to dangerous situations.
The Implications of SCAs:
In this example, the ECU responsible for controlling the headlight system can be exploited through side-channel signals, such as power consumption or electromagnetic emissions. Even though the attack doesn’t require tampering of the ECU, the consequences of such an attack could impact the safety of the vehicle and its passengers.
As vehicles incorporate more automated systems that rely on real-time sensor data, the risk of Side Channel Attacks increases. Securing ECUs from these attacks requires implementation of robust hardware protections, such as shielding sensitive components, reducing side-channel emissions, and performing regular testing to ensure the system is resilient to external monitoring. These measures are essential to maintaining the safety and security of automotive systems in an increasingly connected and automated world.
Understanding Fault Injection Techniques (FIT)
Let’s explore Fault Injection Techniques (FIT) using a healthcare scenario. Consider a Patient Monitoring System (PMS) that uses an MCU (Microcontroller Unit) to manage its operations. A Health care MCU is similar to an Automotive ECU and the MCU handles processing and secure communication in medical devices, such as patient monitoring systems, ensuring accurate patient health data transmission. This PMS system continuously monitors vital signs such as heart rate, blood pressure and oxygen levels and communicates the data to healthcare professionals. Given the critical nature of the data, the MCU is designed to ensure secure and accurate data transmission, making it a potential target for attackers using Fault Injection Techniques.
Fault Injection involves deliberately introducing errors into the system’s operation to cause malfunctions or bypass security mechanisms. In this scenario, attackers may exploit vulnerabilities in the MCU to disrupt the monitoring system, leading to incorrect readings or manipulation of patient data.
Here’s how Fault Injection (types) could target the MCU in a Patient Monitoring System:
1. Voltage Glitching:
In this technique, the attacker rapidly alters the power supply to the MCU, causing it to behave unexpectedly. For example, by reducing the voltage at critical moments when the MCU is processing patient data, the attacker could cause the MCU to malfunction or skip essential operations. This may result in corrupted or delayed data, potentially leading to incorrect health assessments.
2. Clock Glitching:
The attacker can manipulate the clock signal that regulates the timing of the MCU’s operations. By injecting clock glitches, the attacker may disrupt the MCU’s precise timing, causing errors in the patient data processing or communication to external systems. This could lead to the system reporting inaccurate vital signs or even triggering false alarms.
3. Electromagnetic (EM) Fault Injection:
Using electromagnetic interference, the attacker can induce faults in the MCU without physical contact. This method can disrupt the MCU’s normal operations, possibly leading to incorrect sensor readings or bypassing security features designed to protect patient data.
4. Laser Fault Injection:
An attacker with physical access to the device might use laser pulses to target specific areas of the MCU, causing it to malfunction or altering its internal operations. This highly precise method could be used to flip bits in the MCU’s memory, resulting in incorrect data being processed or stored.
Exploitation Phase
Once faults are successfully injected, the attacker can exploit these disruptions. For instance, if the MCU is malfunctioning due to voltage or clock glitches, the attacker could manipulate the system to display inaccurate vital signs, which could lead to incorrect treatments or delayed responses from healthcare professionals. In the worst-case scenario, an attacker might even disable the monitoring system altogether, leaving patients vulnerable to undetected health issues.
The Implications of Fault Injection in Healthcare IoT Systems
In this example, the MCU responsible for monitoring and transmitting critical patient data can be exploited through fault injection techniques like voltage glitching, clock manipulation, or electromagnetic interference. The consequences could be severe, affecting the accuracy and reliability of patient data and, by extension, patient safety.
As healthcare IoT devices become more prevalent, securing MCUs from Fault Injection Attacks is critical. Implementing countermeasures, such as voltage and clock fault detection, shielding components from electromagnetic interference and regularly testing devices for fault injection vulnerabilities, is essential to maintaining the integrity of healthcare systems.
These security measures are crucial in ensuring that patient monitoring devices operate reliably, preventing malicious actors from compromising the safety and well-being of patients.
Understanding Supply Chain Attacks
A Supply Chain Attack occurs when attackers compromise a device or component during its manufacturing, distribution, or assembly process, often before it even reaches the end user. In this type of attack, malicious elements like hardware Trojans, backdoors, or faulty components are introduced into the product, allowing attackers to exploit vulnerabilities later when the device is deployed in critical environments.
Let’s take the recent pager attack as an example to understand how a Supply Chain Attack could work. Pagers are commonly used for communication in various sectors, including healthcare, security and emergency services. In this incident, it is suspected that attackers may have compromised the pagers during manufacturing or distribution, embedding malicious hardware components that enabled remote exploitation of the devices.
Here’s how a Supply Chain Attack might have targeted the pagers:
1. Insertion of Malicious Components:
During the manufacturing or distribution phase, attackers could have inserted hardware Trojans or backdoors into the pagers. These malicious components could remain dormant until triggered by the attacker.
2. Undetected Malicious Behaviour:
Since these modifications are made at the hardware level, they can evade detection during standard quality assurance and testing processes. The pagers may pass all functional tests and be deployed in sensitive environments without raising any red flags. Moreover, the supply chain attack can happen at any level, may be at the design, development or even during deployment. This calls for may mitigation process such as Trusted IC, Watermarking and so on. Below diagram explain the potential stages where Hardware Trojans can be deployed:
3. Exploitation Upon Activation:
Once the pagers are in use, attackers could activate the hidden malicious components remotely. In the case of the Lebanon pager attack, this could have led to system malfunctions, the leaking of sensitive communications, or even a coordinated failure of multiple devices. The exploitation may have contributed to the catastrophic consequences, including unexplained explosions and communication disruptions.
The Implications of Supply Chain Attacks in Critical Systems
Supply Chain Attacks, like the pager incident, highlight the growing threat to hardware security. Compromising devices before they reach end users allows attackers to stealthily exploit vulnerabilities, often without being detected until it’s too late.
Securing the supply chain requires stringent monitoring, including verifying the integrity of hardware components at every stage of production, distribution and assembly. Regular audits, trusted suppliers and secure manufacturing practices are crucial to reducing the risk of Supply Chain Attacks and protecting critical systems from being compromised before they even enter service.
Conclusion: Securing the Future of Hardware
As hardware becomes increasingly integrated into our daily lives, securing it is no longer optional—it’s essential. The convergence of Side-Channel Attacks (SCAs), Fault Injection, and Supply Chain Attacks highlights the rising complexity of modern threats. To ensure the integrity, confidentiality, and availability of critical devices, a proactive approach that incorporates advanced testing methodologies and hardware-based defences is crucial.
This blog summarizes emerging hardware security threats, drawn from real-world incidents and research, stressing the importance of robust protection and testing strategies through Hardware Penetration Testing. By raising awareness of these alarming exploits, we can better prepare for the future of secure communications and systems.
If you’re interested in ECU/MPU Penetration Testing or any form of Hardware Penetration Testing, feel free to reach out to us at connect.nestdigital@nestdigital.net
AUTHOR PROFILE
Johnbasco Vijay Anand is an advisory cyber security architect at NeST Digital Private Limited, where he heads the cyber security competency. He is also a part-time Ph.D. scholar in Quantum Key Distribution. He holds dual master’s degrees in Physics and Computer Application. His area of interest includes Hardware Security, Quantum Fault injection analysis, Quantum-Resistant Hardware, and advanced research in cyber security hardening using Quantum Computing and Artificial Intelligence.