CVE-2023-52794 is a vulnerability identified in the Linux kernel's Intel powerclamp thermal driver component. The issue arises from a mismatch in the parameter retrieval function used for the 'max_idle' variable. Specifically, the kernel code incorrectly uses 'param_get_int' to access 'max_idle', which is defined as a byte-sized parameter. This discrepancy leads to a global out-of-bounds read detected by Kernel Address Sanitizer (KASAN), indicating that the code reads beyond the allocated memory for 'max_idle'. The bug manifests as a KASAN error with a global out-of-bounds read of 4 bytes at an address corresponding to 'max_idle'. The root cause is the improper use of 'param_get_int' instead of the correct 'param_get_byte' function, which when replaced, resolves the issue. This vulnerability is located within the thermal management subsystem of the Linux kernel, specifically affecting Intel powerclamp, a driver responsible for managing CPU thermal throttling by injecting idle cycles to reduce power consumption and heat generation. The vulnerability was publicly disclosed on May 21, 2024, and no known exploits are reported in the wild at this time. The affected versions correspond to specific Linux kernel commits identified by the hash 'ebf519710218814cf827adbf9111af081344c969'. The vulnerability does not have an assigned CVSS score but is recognized by CISA and Linux security teams. The impact is primarily related to kernel stability and potential information disclosure due to out-of-bounds memory reads, which could be leveraged in more complex attack chains if combined with other vulnerabilities.

For European organizations, the impact of CVE-2023-52794 depends on their use of Linux systems running affected kernel versions with the Intel powerclamp driver enabled. Since this vulnerability involves a kernel-level out-of-bounds read, it could lead to system instability or crashes, potentially causing denial of service (DoS) conditions. Although no direct privilege escalation or code execution is indicated, out-of-bounds reads can sometimes be exploited to leak sensitive kernel memory, which could aid attackers in bypassing security mechanisms or escalating privileges when chained with other vulnerabilities. Organizations relying on Linux servers, especially those using Intel CPUs with thermal management features enabled, may face risks to system availability and confidentiality. Critical infrastructure, cloud service providers, and enterprises with large Linux deployments in Europe could be affected if patches are not applied promptly. However, the lack of known exploits and the requirement for specific kernel configurations reduce the immediate threat level. Nonetheless, the vulnerability highlights the importance of maintaining updated kernel versions to ensure system reliability and security.

European organizations should prioritize updating their Linux kernels to versions where this vulnerability is patched, specifically ensuring that the Intel powerclamp driver uses 'param_get_byte' for the 'max_idle' parameter. Kernel updates from trusted Linux distributions (e.g., Debian, Ubuntu, Red Hat, SUSE) should be applied as soon as they include this fix. System administrators should audit their Linux systems to verify if the Intel powerclamp driver is active and if the affected kernel versions are in use. For environments where immediate patching is not feasible, disabling the Intel powerclamp driver can serve as a temporary mitigation, though this may impact thermal management and system performance. Additionally, enabling kernel hardening features such as KASAN during development and testing phases can help detect similar issues early. Monitoring system logs for KASAN or kernel warnings related to powerclamp can provide early indicators of exploitation attempts or instability. Finally, organizations should maintain robust incident response plans to address potential kernel-level vulnerabilities and ensure timely communication with Linux distribution vendors for security updates.