CVE-2023-52450 is a vulnerability identified in the Linux kernel, specifically within the perf subsystem for x86 Intel architectures, related to the uncore performance monitoring unit (UPI) topology discovery code. The flaw arises from a NULL pointer dereference in the function upi_fill_topology(), which is triggered due to an out-of-bound access when indexing the 'upi' pointer array. The root cause is the use of a physical socket ID instead of a logical socket ID in the discover_upi_topology() function, leading to an invalid memory reference at the line 'upi = &type->topology[nid][idx];'. This results in the dereferencing of a NULL pointer, causing a kernel crash (kernel panic) or denial of service (DoS). The vulnerability affects Linux kernel versions identified by the commit hash f680b6e6062ef3c944ffc966d685f067958fca33 and likely earlier versions before the patch. The issue was reserved and published in February 2024, with no known exploits reported in the wild to date. The vulnerability does not require user interaction or authentication to be triggered, as it is within the kernel's performance monitoring subsystem, which can be accessed by privileged users or processes. While it does not directly lead to privilege escalation or arbitrary code execution, the resulting kernel crash can disrupt system availability and stability, impacting critical services running on affected Linux systems.

For European organizations, the impact of CVE-2023-52450 primarily concerns system availability and operational continuity. Linux is widely deployed across European enterprises, government agencies, and critical infrastructure sectors such as telecommunications, finance, healthcare, and manufacturing. A kernel NULL pointer dereference causing system crashes can lead to denial of service, potentially disrupting business operations, data processing, and service delivery. Organizations relying on performance monitoring tools or kernel features related to Intel UPI topology may be particularly affected. Although no direct data breach or privilege escalation is indicated, repeated crashes or instability could increase operational risk, complicate incident response, and reduce confidence in system reliability. In environments with high availability requirements or where Linux servers support critical infrastructure, this vulnerability could have significant operational and reputational consequences if exploited or triggered accidentally.

To mitigate CVE-2023-52450, European organizations should promptly apply the official Linux kernel patches that correct the socket ID handling in the perf/x86/intel/uncore subsystem. Since the vulnerability stems from kernel code, updating to the latest stable Linux kernel version containing the fix is the most effective measure. Organizations should: 1) Identify all Linux systems running affected kernel versions, especially those using Intel x86 architectures with performance monitoring enabled. 2) Test and deploy kernel updates in a controlled manner to minimize downtime and ensure compatibility. 3) Restrict access to performance monitoring interfaces (e.g., perf tools) to trusted and authorized users only, reducing the risk of accidental or malicious triggering. 4) Monitor system logs and kernel crash reports for signs of NULL pointer dereference or related instability. 5) Employ kernel hardening techniques and security modules (e.g., SELinux, AppArmor) to limit the impact of kernel faults. 6) Maintain robust backup and recovery procedures to quickly restore affected systems in case of crashes. These steps go beyond generic advice by focusing on controlled patch deployment, access restriction to vulnerable subsystems, and proactive monitoring tailored to this specific kernel vulnerability.