CVE-2024-35978 is a vulnerability identified in the Linux kernel's Bluetooth subsystem, specifically within the function hci_req_sync_complete(). This function is responsible for managing the synchronization request state in the Host Controller Interface (HCI) layer of the Bluetooth stack. The vulnerability arises from improper memory management: the function fails to free the previously allocated synchronization request state before assigning a reference to a new one. This results in a memory leak, where allocated memory is not released back to the system, potentially leading to resource exhaustion over time. While the vulnerability does not directly enable code execution or privilege escalation, the persistent memory leak can degrade system performance, cause instability, or lead to denial of service (DoS) conditions, especially on systems with heavy Bluetooth usage or limited memory resources. The issue affects multiple versions of the Linux kernel identified by the commit hash f60cb30579d3401cab1ed36b42df5c0568ae0ba7. The vulnerability was publicly disclosed on May 20, 2024, and has been addressed by ensuring that the previous synchronization request state is always freed before assigning a new reference. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The fix is critical for maintaining system stability and preventing potential DoS scenarios related to Bluetooth operations on Linux systems.

For European organizations, the impact of CVE-2024-35978 primarily concerns system reliability and availability. Organizations relying on Linux-based systems with active Bluetooth functionality—such as enterprise laptops, IoT devices, embedded systems, and servers that utilize Bluetooth for peripheral connectivity—may experience gradual degradation in performance or unexpected crashes if the vulnerability is exploited through sustained Bluetooth activity. This could disrupt business operations, particularly in sectors where Bluetooth-enabled devices are integral, such as manufacturing automation, healthcare devices, and logistics tracking. Although the vulnerability does not directly compromise confidentiality or integrity, the resulting denial of service or system instability could indirectly affect operational continuity and availability of critical services. Given the widespread use of Linux in European IT infrastructure, especially in public sector, research institutions, and technology companies, unpatched systems could face increased risk of service interruptions. The absence of known exploits reduces immediate risk, but the vulnerability's presence in the kernel Bluetooth stack means that attackers with local access or the ability to induce Bluetooth traffic could trigger the memory leak over time.

European organizations should prioritize applying the official Linux kernel patch that addresses CVE-2024-35978 as soon as it becomes available in their distribution's updates. Beyond patching, organizations should audit and monitor Bluetooth usage on critical Linux systems to identify unusual or excessive Bluetooth activity that could indicate attempts to exploit the memory leak. Implementing strict access controls to limit which users and processes can interact with Bluetooth interfaces reduces the attack surface. For environments where Bluetooth is not essential, disabling the Bluetooth service or kernel modules can eliminate exposure to this vulnerability. Additionally, organizations should incorporate this vulnerability into their vulnerability management and incident response workflows, ensuring that any signs of system instability or resource exhaustion related to Bluetooth are promptly investigated. Regular system health monitoring, including memory usage and kernel logs, can help detect early signs of exploitation attempts. Finally, educating IT staff about the importance of timely kernel updates and Bluetooth security best practices will enhance overall resilience.