CVE-2024-58069 is a vulnerability identified in the Linux kernel specifically affecting the PCF85063 RTC (Real-Time Clock) driver that interfaces with the NVMEM (Non-Volatile Memory) subsystem. The root cause lies in a mismatch between the variable buffer sizes supported by the nvmem interface and the fixed-size expectations of the regmap interface. The regmap interface operates on fixed-size storage, typically expecting buffers to be at least 4 bytes (the size of an unsigned int). However, if an nvmem client requests a buffer smaller than 4 bytes, the regmap_read function may perform an out-of-bounds (OOB) write because it assumes the buffer points to an unsigned int. This OOB write can lead to memory corruption, potentially destabilizing the kernel or enabling privilege escalation or arbitrary code execution under certain conditions. The vulnerability is addressed by introducing an intermediary unsigned int variable to safely hold the read value before copying it to the client buffer, thereby preventing the OOB write. The affected versions are identified by a specific commit hash repeated multiple times, indicating the vulnerability is present in certain Linux kernel builds prior to the patch. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability was published on March 6, 2025.

For European organizations, the impact of CVE-2024-58069 depends on the deployment of Linux systems using the affected PCF85063 RTC driver and the NVMEM subsystem. Since Linux is widely used across servers, embedded devices, and IoT systems, any device or server running an unpatched kernel version with this driver could be vulnerable. The OOB write could lead to kernel memory corruption, potentially causing system crashes (denial of service) or enabling attackers to escalate privileges or execute arbitrary code with kernel-level permissions. This is particularly critical for infrastructure providers, cloud services, telecom operators, and industrial control systems relying on Linux-based embedded devices. The vulnerability could undermine system integrity and availability, impacting critical services and data confidentiality if exploited. However, the lack of known exploits and the requirement for specific conditions (use of the PCF85063 RTC driver with small buffer sizes) somewhat limits immediate widespread impact. Nonetheless, the potential for severe kernel-level compromise makes this a significant threat for organizations with Linux-based infrastructure in Europe.

European organizations should prioritize updating their Linux kernels to the latest patched versions that include the fix for CVE-2024-58069. Specifically, kernel maintainers and system administrators should verify if their systems use the PCF85063 RTC driver and the NVMEM subsystem. For embedded and IoT devices, firmware updates incorporating the patched kernel should be deployed promptly. Additionally, organizations should audit their systems to identify any applications or drivers that interact with the NVMEM interface using buffers smaller than 4 bytes, as these are the vectors triggering the vulnerability. Employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and enabling security modules like SELinux or AppArmor can reduce exploitation risk. Monitoring kernel logs for unusual behavior and implementing strict access controls to limit unprivileged user access to kernel interfaces can further mitigate risk. Finally, organizations should maintain an up-to-date inventory of Linux kernel versions in use and subscribe to security advisories to respond rapidly to emerging threats.