CVE-2024-35933 is a vulnerability identified in the Linux kernel's Bluetooth subsystem, specifically within the btintel driver component responsible for handling Intel Bluetooth devices. The issue arises when the function hci_cmd_sync_complete() is triggered and the socket buffer (skb) parameter is NULL. This condition leads to the hdev->req_skb pointer being NULL, which subsequently causes a null pointer dereference. Null pointer dereference vulnerabilities typically result in a kernel crash (kernel panic), leading to a denial of service (DoS) condition. The vulnerability is rooted in improper handling of asynchronous Bluetooth HCI command completions, where the code does not adequately check for NULL skb before dereferencing it. The affected versions are identified by a specific commit hash (1da177e4c3f41524e886b7f1b8a0c1fc7321cac2), indicating that the flaw exists in certain recent Linux kernel builds prior to the patch. The vulnerability does not currently have any known exploits in the wild, and no CVSS score has been assigned yet. However, the Linux project has published a fix to address this null pointer dereference by adding appropriate NULL checks to prevent the kernel from crashing when the skb is NULL. Since the Bluetooth stack is a core component in many Linux-based systems, this vulnerability could be triggered remotely or locally depending on the Bluetooth device interaction and driver usage. The flaw primarily impacts system stability and availability rather than confidentiality or integrity, as it leads to kernel crashes rather than privilege escalation or data leakage.

For European organizations, the impact of CVE-2024-35933 centers on potential denial of service conditions on Linux systems utilizing affected Bluetooth drivers. Many enterprises, government agencies, and critical infrastructure operators in Europe rely on Linux-based servers, desktops, and embedded devices that may have Bluetooth enabled for device connectivity. A successful exploitation could cause system crashes, leading to service interruptions, operational downtime, and potential disruption of business processes reliant on affected systems. In environments where Bluetooth is used for device management, asset tracking, or secure communications, this vulnerability could degrade operational reliability. Although no direct data breach or privilege escalation is indicated, repeated or targeted exploitation could be leveraged as part of a broader attack to disrupt services or create windows for further intrusion. The lack of known exploits reduces immediate risk, but the widespread use of Linux in European IT infrastructure means that unpatched systems remain vulnerable to accidental or malicious triggering of this flaw. Organizations with Bluetooth-enabled Linux endpoints, including IoT devices, industrial control systems, and user workstations, should be particularly vigilant.

European organizations should prioritize updating their Linux kernels to versions that include the patch for CVE-2024-35933 as soon as vendor updates are available. Specifically, they should: 1) Identify all Linux systems with Bluetooth enabled and verify kernel versions against the patched commit. 2) Apply vendor-supplied kernel updates or backported patches promptly to eliminate the null pointer dereference. 3) Where immediate patching is not feasible, consider disabling Bluetooth functionality on critical systems to mitigate risk temporarily. 4) Monitor system logs and kernel messages for signs of Bluetooth-related crashes or anomalies that could indicate attempted exploitation. 5) Implement network segmentation and access controls to limit exposure of Bluetooth-enabled devices, especially in sensitive environments. 6) Engage with Linux distribution vendors and maintain awareness of further advisories related to Bluetooth kernel components. 7) Conduct internal testing to ensure that Bluetooth-dependent applications and devices continue to function correctly after patching. These steps go beyond generic advice by focusing on Bluetooth-specific kernel components and operational controls tailored to the vulnerability's nature.