CVE-2023-53018 is a vulnerability identified in the Linux kernel's Bluetooth subsystem, specifically within the handling of Bluetooth Low Energy (LE) connections. The issue arises in the functions hci_le_terminate_big() and hci_le_big_terminate(), which are responsible for terminating Bluetooth LE BIG (Broadcast Isochronous Group) connections. When the internal function hci_cmd_sync_queue() fails during these termination processes, the memory pointed to by the variable 'd' is not properly freed, resulting in a memory leak. This leak occurs because the error path lacks the necessary release process to free allocated memory. While the vulnerability does not directly lead to code execution or privilege escalation, persistent memory leaks can degrade system performance, potentially leading to denial of service (DoS) conditions if exploited over time. The vulnerability affects Linux kernel versions identified by the commit hash eca0ae4aea66914515e5e3098ea051b518ee5316, and it has been addressed by adding the missing memory release in the error handling path. There are currently no known exploits in the wild, and no CVSS score has been assigned to this vulnerability. The issue is primarily relevant to systems utilizing Bluetooth LE BIG features, which are more common in modern Bluetooth-enabled devices and embedded systems running Linux kernels with Bluetooth support.

For European organizations, the impact of CVE-2023-53018 is primarily related to system stability and availability rather than direct compromise of confidentiality or integrity. Organizations relying on Linux-based systems with Bluetooth LE capabilities—such as IoT devices, embedded systems, industrial control systems, and enterprise endpoints—may experience gradual degradation of system resources due to memory leaks if the vulnerability is triggered repeatedly. This could lead to increased maintenance costs, potential downtime, and reduced reliability of Bluetooth-dependent services. In sectors like manufacturing, healthcare, and transportation where Bluetooth-enabled devices are integral, such degradation could disrupt operations. However, since exploitation requires triggering specific Bluetooth LE BIG termination sequences and does not appear to allow remote code execution or privilege escalation, the risk of severe security breaches is low. Nonetheless, the vulnerability could be leveraged as part of a broader attack strategy aimed at causing denial of service or distracting security teams.

To mitigate CVE-2023-53018, European organizations should prioritize updating their Linux kernel to the patched version that includes the fix for this memory leak. Kernel updates should be tested and deployed promptly on all systems utilizing Bluetooth LE features. For environments where immediate patching is not feasible, organizations should consider disabling Bluetooth LE BIG functionality if it is not required, thereby reducing the attack surface. Monitoring system logs and resource usage for unusual memory consumption related to Bluetooth processes can help detect potential exploitation attempts. Additionally, implementing strict access controls and network segmentation for devices with Bluetooth capabilities can limit exposure. Organizations should also maintain an inventory of Linux-based devices with Bluetooth LE support to ensure comprehensive coverage during patch management. Finally, educating system administrators about this vulnerability and its implications will support timely response and remediation.