CVE-2021-47313 is a high-severity vulnerability identified in the Linux kernel's cpufreq subsystem, specifically within the Collaborative Processor Performance Control (CPPC) component. The vulnerability is a classic memory leak issue occurring during the initialization of CPU frequency policies (cppc_cpufreq_cpu_init). When the system attempts to allocate resources for CPU frequency scaling policies and the initialization fails, the allocated memory is not properly freed, leading to a memory leak. This flaw can cause the kernel to consume increasing amounts of memory over time, potentially degrading system performance or causing instability. The vulnerability affects specific Linux kernel versions identified by commit hashes (a28b2bfc099c6b9caa6ef697660408e076a32019). The CVSS v3.1 score is 8.4, indicating a high severity with the vector AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, meaning the attack requires local access but no privileges or user interaction, and can lead to high impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the vulnerability's nature and impact make it a critical issue for systems relying on affected Linux kernel versions. The root cause is improper resource management during failure conditions in CPU frequency policy initialization, which can be exploited by local attackers to cause denial of service or potentially escalate privileges by destabilizing kernel memory management. The fix involves ensuring all allocated resources are freed upon initialization failure to prevent memory leaks.

For European organizations, the impact of CVE-2021-47313 can be significant, especially for those relying heavily on Linux-based infrastructure, including servers, cloud environments, and embedded systems. The memory leak can lead to gradual resource exhaustion, causing system slowdowns, crashes, or denial of service, which can disrupt critical business operations, data processing, and service availability. The high confidentiality, integrity, and availability impact means that sensitive data could be at risk if system stability is compromised, potentially leading to data corruption or unauthorized access if attackers leverage the instability for privilege escalation. Industries such as finance, healthcare, telecommunications, and government agencies in Europe that depend on Linux for secure and stable operations could face operational disruptions and compliance risks. Additionally, the requirement for local access to exploit the vulnerability limits remote exploitation but does not eliminate insider threats or risks from compromised local accounts. The absence of known exploits in the wild currently reduces immediate risk but does not preclude future exploitation, making timely patching critical to maintaining security posture.

European organizations should prioritize updating their Linux kernel to versions where this vulnerability is patched. Since the issue lies in the kernel's cpufreq CPPC initialization, applying vendor-supplied kernel updates or patches is the most effective mitigation. For environments where immediate patching is not feasible, organizations should implement strict access controls to limit local user access, especially restricting unprivileged users from executing code or commands that could trigger the vulnerability. Monitoring system memory usage and kernel logs for unusual behavior can help detect early signs of exploitation or memory leaks. Employing kernel hardening techniques such as SELinux or AppArmor can reduce the risk of privilege escalation attempts. Organizations should also review and restrict the use of CPU frequency scaling features if not required, as disabling or limiting cpufreq functionality may reduce the attack surface. Finally, maintaining an up-to-date inventory of Linux kernel versions in use across all systems will facilitate rapid identification and remediation of vulnerable hosts.