CVE-2024-56603 is a high-severity vulnerability in the Linux kernel's CAN (Controller Area Network) protocol implementation, specifically within the af_can socket creation function (can_create()). The issue arises because, on encountering an error, can_create() frees the allocated socket (sk) object; however, sock_init_data() has already attached this sk object to the provided sock object. This sequence results in a dangling pointer within the sock object, leading to a use-after-free (UAF) condition. Use-after-free vulnerabilities are critical because they allow attackers to manipulate freed memory, potentially leading to arbitrary code execution, privilege escalation, or system crashes. The vulnerability is classified under CWE-416 (Use After Free). The CVSS v3.1 score is 7.8 (high), with vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, indicating that the attack requires local access with low complexity, low privileges, no user interaction, and can impact confidentiality, integrity, and availability at a high level. The affected component is the Linux kernel's CAN protocol stack, which is used primarily in automotive and industrial control systems for real-time communication. The vulnerability was published on December 27, 2024, and no known exploits in the wild have been reported yet. The patch details are not provided in the source data, but the issue has been resolved in the Linux kernel source. This vulnerability is significant because the CAN protocol is often used in embedded systems and IoT devices running Linux, which may be part of critical infrastructure or industrial environments. Exploitation could allow a local attacker to escalate privileges or cause denial of service by crashing the kernel or executing arbitrary code in kernel space.

For European organizations, the impact of CVE-2024-56603 can be substantial, especially for those operating in sectors relying on Linux-based embedded systems, such as automotive manufacturers, industrial automation, energy, and critical infrastructure. The CAN protocol is widely used in vehicle networks and industrial control systems, which are prevalent in Europe’s automotive industry and manufacturing sectors. Exploitation could lead to unauthorized control over critical systems, data breaches, or disruption of services. This could result in safety risks (e.g., in automotive or industrial environments), financial losses, regulatory penalties under GDPR if personal data is compromised, and reputational damage. Since the vulnerability requires local access with low privileges, insider threats or compromised user accounts could be leveraged to exploit this flaw. Additionally, the high impact on confidentiality, integrity, and availability means that attackers could potentially execute arbitrary code with kernel privileges, leading to full system compromise. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

1. Immediate application of the official Linux kernel patches that address CVE-2024-56603 is critical. Organizations should track kernel updates from trusted sources and deploy them promptly. 2. Restrict local access to systems running vulnerable Linux kernels, enforcing strict access controls and monitoring for suspicious activity to reduce the risk of exploitation by low-privilege users. 3. Implement kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and use of security modules like SELinux or AppArmor to limit the impact of potential exploitation. 4. For embedded and IoT devices using Linux with CAN protocol support, ensure firmware updates are applied and consider network segmentation to isolate these devices from broader enterprise networks. 5. Conduct regular vulnerability scanning and penetration testing focused on local privilege escalation and kernel vulnerabilities to detect potential exploitation attempts. 6. Employ strict user privilege management and audit logs to detect and respond to anomalous local activities. 7. Collaborate with vendors and suppliers to ensure that all Linux-based devices, especially in automotive and industrial environments, are updated and secured against this vulnerability.