CVE-2026-82357 in C-Open
Summary
by MITRE • 10/01/2026
RT-Labs AB C-Open CANopen contains a NULL pointer dereference if the LSS protocol is used to configure the device. An object defined by the user application may not have all required subindexes for object 0x1018. An unauthenticated, remote attacker with access to the CAN bus, through a compromised node for instance, can initiate the LSS protocol on a device with a misconfigured identity object and potentially crash the device. Fixed in 1.1.1.
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Analysis
by VulDB Data Team • 10/01/2026
The vulnerability identified within RT-Labs AB C-Open CANopen represents a critical security flaw rooted in improper input validation during the execution of the Layer Service Specification protocol, commonly referred to as LSS. This protocol is essential for configuring and managing devices on a Controller Area Network bus, allowing masters to discover slaves and assign addresses or other configuration parameters. The specific technical defect involves a NULL pointer dereference that occurs when the application attempts to process identity object data associated with subindex 0x1018. In standard CANopen implementations, this object is intended to store identification information such as vendor ID, product code, revision number, and serial number. However, the vulnerability arises because the software does not rigorously verify that all required subindexes for this object are present or correctly initialized before attempting to access them. If a user application defines an incomplete identity object structure, the internal pointer referencing these missing fields remains null rather than being safely handled or defaulted.
From an operational perspective, this flaw allows any unauthenticated actor with physical or logical access to the CAN bus to exploit the condition by initiating LSS configuration procedures against a target device that possesses this misconfigured identity object state. The attacker does not need valid credentials because the vulnerability is triggered during standard protocol operations rather than through privileged administrative commands. By sending specific LSS messages, an unauthenticated remote attacker can force the vulnerable node into a state where it attempts to dereference the null pointer. This action typically results in a hard fault or exception within the embedded system's operating environment, leading to an immediate crash of the device. Such a denial-of-service condition disrupts communication on the network segment and may require manual intervention or power cycling to restore functionality, thereby impacting the availability and reliability of industrial automation systems that rely on stable CANopen connectivity.
This vulnerability aligns with CWE-476, which describes NULL Pointer Dereference vulnerabilities where software fails to check for null pointers before using them as valid memory addresses. Furthermore, in the context of the MITRE ATT&CK framework, this exploit scenario corresponds to techniques involving Denial of Service and potentially Initial Access if the crash is used to facilitate further exploitation or disrupt critical infrastructure operations. The attack vector leverages the inherent trust often placed in CAN bus communications, where devices frequently assume that incoming messages are from legitimate sources unless explicitly secured by additional mechanisms like SecOC which may not be enabled or configured correctly in all deployments.
To mitigate this risk, organizations should ensure they upgrade to version 1.1.1 of C-Open CANopen, which contains the necessary code fixes to validate object subindexes before access. For systems that cannot immediately update due to legacy constraints, defensive measures include implementing strict network segmentation to isolate critical CAN bus segments from potentially compromised nodes or external interfaces. Additionally, deploying intrusion detection systems capable of monitoring for anomalous LSS traffic patterns can help identify attempted exploitation activities. Developers integrating this library must also enforce rigorous validation rules during the application layer configuration phase, ensuring that all mandatory subindexes for identity objects are populated and verified prior to any protocol interaction. Regular security audits of embedded firmware configurations and adherence to secure coding standards such as MISRA C can further reduce the likelihood of similar pointer-related vulnerabilities in future deployments.