CVE-2022-2741 is a high-severity vulnerability in the Zephyr real-time operating system (RTOS), specifically related to its Controller Area Network (CAN) protocol implementation. The vulnerability is classified as an uncontrolled resource consumption issue (CWE-400), which can lead to a denial-of-service (DoS) condition. The attack vector involves transmitting a specially crafted CAN frame on the same CAN network as the vulnerable node. The malicious frame must have a CAN ID that matches an installed filter on the target node, which can be deduced through traffic analysis of the CAN bus. Additionally, the frame must have the opposite Remote Transmission Request (RTR) bit value compared to what the filter expects—if the filter matches RTR frames, the attacker sends a data frame, and vice versa. This mismatch causes the vulnerable node to consume excessive resources, leading to a denial of service. The vulnerability does not require authentication or user interaction and can be exploited remotely over the CAN network. The CVSS 3.1 base score is 8.2, reflecting high severity, with the vector indicating network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality impact, low integrity impact, and high availability impact. No known exploits are currently reported in the wild, and no specific patched versions are listed, indicating that mitigation may require custom fixes or updates from the Zephyr project. This vulnerability is particularly relevant for embedded systems using Zephyr RTOS with CAN bus communication, such as automotive, industrial control, and IoT devices.

For European organizations, the impact of CVE-2022-2741 can be significant, especially those involved in automotive manufacturing, industrial automation, and critical infrastructure sectors that utilize embedded systems running Zephyr RTOS with CAN bus interfaces. Exploitation can cause denial of service on affected nodes, potentially disrupting vehicle subsystems, industrial control processes, or IoT device operations. This can lead to operational downtime, safety risks, and financial losses. Given the widespread use of CAN networks in automotive and industrial environments, this vulnerability could affect supply chains and critical services. The lack of confidentiality impact reduces risks related to data breaches, but the integrity and availability impacts are concerning, as attackers can disrupt system functionality. European organizations with connected vehicles, smart factories, or critical infrastructure relying on Zephyr RTOS must consider this threat seriously to maintain operational continuity and safety compliance.

To mitigate CVE-2022-2741, European organizations should: 1) Monitor Zephyr project updates closely and apply patches or firmware updates as soon as they become available. 2) Implement network segmentation and isolation for CAN networks to limit exposure to untrusted devices or external networks. 3) Employ CAN bus traffic monitoring and anomaly detection to identify unusual frames, especially those with suspicious CAN IDs or RTR bit mismatches. 4) Restrict physical and logical access to CAN networks to prevent unauthorized frame injection. 5) Where possible, configure CAN filters more restrictively to reduce the attack surface and avoid accepting frames with unexpected RTR bit values. 6) Collaborate with device and system vendors to ensure secure firmware updates and incorporate secure boot mechanisms to prevent unauthorized code execution. 7) Conduct security assessments and penetration testing focused on CAN bus interfaces and Zephyr RTOS implementations to identify and remediate vulnerabilities proactively.