CVE-2021-47050 is a vulnerability identified in the Linux kernel specifically within the memory management code related to the Renesas RPC interface (renesas-rpc-if). The issue arises from improper handling of a NULL pointer returned by the function platform_get_resource_byname(). This function is designed to retrieve a hardware resource by name, but in some cases, it may return NULL if the resource is not found. The vulnerability occurs because the returned pointer is dereferenced immediately by resource_size() without validating whether it is NULL, leading to a potential NULL pointer dereference. This can cause the kernel to crash or behave unpredictably, resulting in a denial of service (DoS) condition. The patch for this vulnerability involves adding a check to ensure the resource pointer is not NULL before dereferencing it, thereby preventing the kernel from crashing due to this error. The vulnerability was discovered and resolved in early 2024, with no known exploits in the wild at the time of publication. It affects certain versions of the Linux kernel containing the vulnerable code, particularly those using the Renesas RPC interface, which is common in embedded systems and specialized hardware platforms. Since this flaw is a NULL pointer dereference, it primarily impacts system stability and availability rather than confidentiality or integrity. Exploitation does not require user interaction but does require the vulnerable kernel to be running on affected hardware. No CVSS score has been assigned yet, but the technical details and patch information are publicly available.

For European organizations, the primary impact of CVE-2021-47050 is on system availability and stability. Systems running vulnerable Linux kernels with the Renesas RPC interface could experience kernel crashes leading to denial of service. This is particularly relevant for organizations relying on embedded Linux devices or specialized industrial hardware that use Renesas processors or similar platforms. Critical infrastructure sectors such as manufacturing, telecommunications, and transportation in Europe that deploy such embedded Linux systems could face operational disruptions if the vulnerability is exploited or triggered unintentionally. Although no known exploits exist currently, the risk remains that attackers or malware could leverage this flaw to cause system outages. The impact on confidentiality and integrity is minimal, as the vulnerability does not provide direct access or privilege escalation. However, availability issues in critical systems can indirectly affect business continuity and safety. Organizations with Linux-based IoT devices or industrial control systems should be especially vigilant, as these environments often have longer patch cycles and may be more exposed to stability issues.

European organizations should prioritize applying the official Linux kernel patches that address CVE-2021-47050 as soon as they become available for their specific distributions and hardware platforms. For embedded and industrial systems, coordination with hardware vendors and system integrators is essential to obtain updated firmware or kernel versions. In environments where immediate patching is not feasible, organizations should implement monitoring to detect kernel crashes or abnormal system reboots that could indicate exploitation attempts. Restricting access to vulnerable systems and limiting exposure to untrusted networks can reduce the risk of exploitation. Additionally, organizations should review their use of the Renesas RPC interface and assess whether alternative hardware or software configurations can be employed to mitigate risk. Regular kernel updates and vulnerability scanning should be integrated into the patch management lifecycle, especially for embedded Linux devices. Finally, maintaining robust incident response plans to quickly address any denial of service incidents will help minimize operational impact.