CVE-2018-18070 in Mercedes Comand
Summary
by MITRE
An issue was discovered in Daimler Mercedes-Benz COMAND 17/13.0 50.12 on Mercedes-Benz C-Class 2018 vehicles. Defining or receiving a specific navigation route might cause the system to freeze and reboot after a few transmissions. When the system next starts, it tries to re-calculate the route, which will cause a boot loop. (Under certain circumstances, it is possible to quickly overwrite the malicious route to regain the stability of the system.)
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/23/2023
This vulnerability affects the COMAND infotainment system version 17/13.0 50.12 installed in 2018 Mercedes-Benz C-Class vehicles, representing a critical software flaw that demonstrates poor input validation and error handling in automotive embedded systems. The issue manifests when the system processes specific navigation route data, triggering a cascade of system failures that ultimately result in a boot loop condition. This vulnerability falls under CWE-248, an unspecified language error that can lead to unexpected behavior in software applications, and specifically relates to improper handling of malformed input data within the navigation subsystem. The attack surface is particularly concerning as it involves the vehicle's primary user interface for navigation and entertainment, potentially providing adversaries with persistent control over critical vehicle systems.
The technical exploitation of this vulnerability occurs through the manipulation of navigation route data, where specific parameters or data structures cause the system to enter an unstable state. When a malicious or malformed route is defined or received, the system experiences a freeze followed by automatic rebooting, indicating a lack of proper exception handling and system recovery mechanisms. The subsequent boot loop represents a classic example of a denial-of-service condition that can be difficult to recover from without physical intervention, as the system attempts to re-calculate the problematic route during each boot cycle. This behavior aligns with ATT&CK technique T1499.001, which involves malicious code that causes system instability or crashes, and demonstrates how automotive systems can be made vulnerable through seemingly benign user inputs.
The operational impact of this vulnerability extends beyond simple system inconvenience to potentially compromising vehicle safety and usability. In a real-world scenario, drivers could find themselves unable to use the vehicle's navigation system, which may force them to rely on external devices or manual navigation methods. The boot loop condition creates a situation where the vehicle's infotainment system becomes completely non-functional until the malicious route data is overwritten, potentially occurring during critical driving situations. The fact that quick overwrite of the malicious route can restore stability indicates that the vulnerability is not permanent but rather represents a temporary system corruption that can be remediated through specific recovery procedures, though this requires technical knowledge and access to the system's data storage mechanisms.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and error recovery mechanisms within the navigation subsystem. System designers should incorporate proper exception handling that prevents malformed route data from causing system crashes, while also implementing automatic backup and restore functionality that can recover from corrupted navigation data without requiring complete system reboot. The solution should include defensive programming practices that align with automotive security standards such as ISO/SAE 21434, which provides guidelines for cybersecurity throughout the vehicle lifecycle. Additionally, regular software updates and patches should be implemented to address known vulnerabilities, and system monitoring should be enhanced to detect unusual patterns in route calculation that might indicate malicious input attempts. Organizations should also consider implementing network segmentation and access controls for vehicle systems to limit the potential impact of such vulnerabilities and ensure that only authorized inputs can affect critical vehicle functions.