CVE-2024-41149 is a high-severity vulnerability identified in the Linux kernel's block layer, specifically related to the handling of the hardware context (hctx) within the CPU hotplug (cpuhp) callback list. The vulnerability arises when the hctx is not properly removed from the cpuhp callback list before reuse. If the hctx remains in the callback list and is subsequently reused, a use-after-free condition can occur. Use-after-free vulnerabilities are critical because they allow attackers to interact with memory that has been freed, potentially leading to arbitrary code execution, privilege escalation, or system crashes. The vulnerability is tracked under CWE-416 (Use After Free) and has a CVSS 3.1 base score of 7.8, indicating a high impact on confidentiality, integrity, and availability. The attack vector is local (AV:L), requiring low attack complexity (AC:L) and low privileges (PR:L), but no user interaction (UI:N). This means an attacker with limited local access can exploit the flaw without needing to trick a user. The scope is unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). The vulnerability affects specific Linux kernel versions identified by commit hashes, implying it targets recent kernel builds. No known exploits are currently reported in the wild, but the nature of the flaw suggests that exploitation could lead to severe consequences such as kernel-level code execution or denial of service. The issue was resolved by ensuring that the hctx is properly removed from the cpuhp callback list before reuse, preventing the use-after-free condition. This vulnerability is particularly relevant for systems running Linux kernels with the affected commits, especially those that utilize CPU hotplug features and block device operations.

For European organizations, this vulnerability poses a significant risk, especially for enterprises relying heavily on Linux-based infrastructure, including servers, cloud environments, and embedded systems. Exploitation could lead to full system compromise, allowing attackers to escalate privileges to kernel level, execute arbitrary code, or cause system outages. This can disrupt critical services, lead to data breaches, and impact business continuity. Given the local attack vector, the threat is more pronounced in environments where multiple users have local access or where attackers can gain initial footholds through other means (e.g., compromised user accounts or containers). The high impact on confidentiality, integrity, and availability means sensitive data could be exposed or altered, and critical systems could be rendered unavailable. This is particularly concerning for sectors such as finance, healthcare, telecommunications, and government agencies within Europe, where Linux servers are prevalent and data protection regulations like GDPR impose strict requirements on data security and breach notification.

European organizations should prioritize patching affected Linux kernel versions as soon as updates become available from their distribution vendors or the Linux kernel maintainers. Since the vulnerability involves kernel-level code, applying official kernel patches or upgrading to a fixed kernel version is the most effective mitigation. Additionally, organizations should: 1) Limit local access to critical Linux systems by enforcing strict access controls and monitoring for unauthorized local logins. 2) Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and Control Flow Integrity (CFI) to reduce exploitation likelihood. 3) Use security modules like SELinux or AppArmor to restrict the capabilities of processes and users. 4) Monitor system logs and kernel messages for unusual behavior indicative of exploitation attempts. 5) In virtualized or containerized environments, isolate workloads to minimize the impact of a potential kernel exploit. 6) Conduct regular security audits and vulnerability scans to identify unpatched systems. 7) Educate system administrators about the risks of local privilege escalation vulnerabilities and the importance of timely patch management.