CVE-2024-35966 is a vulnerability identified in the Linux kernel's Bluetooth RFCOMM protocol implementation. Specifically, the issue lies in the rfcomm_sock_setsockopt_old() function, which improperly handles user input when processing setsockopt system calls. The vulnerability arises because this function copies data from user space without validating the length of the input, leading to a potential slab-out-of-bounds read as detected by Kernel Address Sanitizer (KASAN). The out-of-bounds read occurs in the copy_from_sockptr and copy_from_sockptr_offset functions within the sockptr.h kernel headers, which are used to safely copy data from socket pointers. This flaw can cause memory corruption or kernel crashes due to accessing invalid memory regions. The vulnerability was reported by syzbot, an automated kernel fuzzing tool, and affects multiple versions of the Linux kernel identified by the commit hash bb23c0ab824653be4aa7dfca15b07b3059717004. Although no known exploits are currently reported in the wild, the flaw represents a serious risk because it involves kernel-level code and Bluetooth, a widely used communication protocol. The vulnerability does not have an assigned CVSS score yet but has been officially published and acknowledged by the Linux project. The root cause is the lack of proper input validation on user-supplied data in a kernel socket option handler, which is a common source of security issues in kernel code. This vulnerability could potentially be exploited by a local attacker or malicious Bluetooth device to cause denial of service or possibly escalate privileges by triggering kernel memory corruption.

For European organizations, the impact of CVE-2024-35966 can be significant, especially those relying heavily on Linux-based systems with Bluetooth capabilities. Many enterprises, government agencies, and critical infrastructure operators in Europe use Linux servers, desktops, and embedded devices that support Bluetooth RFCOMM for communication or device management. Exploitation of this vulnerability could lead to kernel crashes causing denial of service, disrupting business operations or critical services. More severe exploitation might allow attackers to execute arbitrary code at the kernel level, potentially leading to privilege escalation and full system compromise. This is particularly concerning for sectors such as telecommunications, manufacturing, healthcare, and transportation, where Linux-based embedded systems with Bluetooth are common. Additionally, the vulnerability could be leveraged in targeted attacks against European organizations by adversaries aiming to disrupt operations or gain unauthorized access. Since Bluetooth is a wireless protocol, the attack surface includes not only local users but also nearby malicious devices, increasing the risk in environments with many Bluetooth-enabled devices. The lack of known exploits currently reduces immediate risk but does not eliminate the threat, as proof-of-concept exploits could emerge rapidly once the vulnerability details are public.

To mitigate CVE-2024-35966, European organizations should take the following specific actions: 1) Apply the official Linux kernel patches that address this vulnerability as soon as they become available from trusted sources or Linux distribution vendors. 2) For systems where immediate patching is not feasible, consider disabling Bluetooth RFCOMM support temporarily if it is not essential, to reduce the attack surface. 3) Implement strict access controls and monitoring on systems with Bluetooth enabled, including limiting user privileges to prevent unauthorized use of setsockopt calls. 4) Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), kernel lockdown modes, and use of security modules like SELinux or AppArmor to limit the impact of potential exploitation. 5) Monitor system logs and kernel messages for unusual activity related to Bluetooth socket operations that could indicate exploitation attempts. 6) Educate IT and security teams about the vulnerability and ensure incident response plans include scenarios involving kernel-level Bluetooth vulnerabilities. 7) Coordinate with Bluetooth device manufacturers and vendors to ensure firmware updates do not introduce related vulnerabilities and maintain secure Bluetooth configurations. These targeted measures go beyond generic advice by focusing on the specific nature of the vulnerability and its exploitation vectors.