CVE-2022-49275 is a high-severity use-after-free vulnerability in the Linux kernel's CAN (Controller Area Network) subsystem, specifically affecting the m_can driver implementation. The vulnerability arises in the m_can_tx_handler() function, where the handling of socket buffers (skb) is flawed. The function can_put_echo_skb() clones the skb and then frees the original skb. However, in the affected versions of the Linux kernel, the timing and order of these operations are incorrect, leading to a use-after-free condition. This means that after the skb is freed, subsequent code may still reference it, potentially leading to memory corruption. The issue is related to the m_can version 3.0.x branch, where the fix involves moving the can_put_echo_skb() call directly before the start of the hardware transmission (xmit), aligning it with the approach used in the 3.1.x branch. Exploiting this vulnerability could allow a local attacker with low privileges (PR:L) and no user interaction (UI:N) to execute arbitrary code or cause denial of service by corrupting kernel memory. The CVSS 3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. The vulnerability is categorized under CWE-416 (Use After Free). No known exploits are currently reported in the wild, but the potential for exploitation exists given the nature of the flaw and the critical role of the kernel in system security and stability.

For European organizations, the impact of CVE-2022-49275 could be significant, especially for those relying on Linux-based systems in environments where CAN bus communication is used. This includes automotive manufacturers, industrial control systems, embedded device manufacturers, and critical infrastructure sectors such as energy and transportation. Exploitation could lead to unauthorized code execution at the kernel level, compromising system confidentiality and integrity, or cause denial of service, disrupting operations. Given the widespread use of Linux in servers, embedded devices, and IoT systems across Europe, the vulnerability poses a risk to both enterprise IT environments and operational technology (OT) networks. The potential for lateral movement and privilege escalation within networks could also increase the threat landscape. The absence of known exploits currently provides a window for proactive mitigation, but organizations should not underestimate the risk due to the high severity and kernel-level impact.

European organizations should prioritize patching affected Linux kernel versions as soon as vendor updates become available, ensuring that the fix moving can_put_echo_skb() before hardware transmission is applied. In addition to patching, organizations should: 1) Audit and monitor systems that utilize CAN bus interfaces, particularly embedded and industrial devices, for unusual behavior or signs of exploitation. 2) Implement strict access controls to limit local user privileges, as exploitation requires at least low-level privileges. 3) Employ kernel security hardening techniques such as Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and seccomp filters to reduce attack surface. 4) Use intrusion detection systems capable of monitoring kernel-level anomalies and CAN bus traffic irregularities. 5) For embedded and IoT devices, ensure secure firmware update mechanisms are in place to deploy patches promptly. 6) Conduct thorough risk assessments for systems integrating CAN communication to identify and isolate critical assets. These measures, combined with timely patching, will reduce the likelihood and impact of exploitation.