CVE-2023-52670 is a vulnerability identified in the Linux kernel specifically related to the rpmsg (remote processor messaging) subsystem using virtio transport. The issue arises from improper handling of the driver_override field during the rpmsg_remove() function call. When rpmsg_remove() is invoked, the driver_override pointer is not freed correctly, leading to a memory leak. This leak manifests as unreferenced kernel objects accumulating over time, which can degrade system performance or stability. The vulnerability is rooted in a use-after-free or improper resource management scenario, classified under CWE-401 (Improper Release of Memory Before Removing Last Reference). The technical details include a backtrace showing kernel functions involved, such as __kmem_cache_alloc_node, __kmalloc_node_track_caller, kstrndup, driver_set_override, and rpmsg_register_device_override, indicating the memory allocation and driver override registration processes are implicated. The vulnerability was patched by ensuring the driver_override is freed during rpmsg_remove(), preventing the memory leak. The CVSS v3.1 score is 6.6 (medium severity), with vector AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, indicating the attack vector is physical (local), low attack complexity, no privileges required, user interaction required, unchanged scope, and high impact on confidentiality, integrity, and availability. No known exploits are reported in the wild as of publication. The affected versions are specific Linux kernel commits identified by hash, implying this affects certain kernel builds before the patch date (May 17, 2024).

For European organizations, this vulnerability poses a moderate risk primarily in environments where Linux kernels with the vulnerable rpmsg subsystem are deployed, especially in embedded systems, industrial control systems, or specialized hardware using remote processor messaging via virtio. The memory leak can lead to resource exhaustion, causing system slowdowns, crashes, or denial of service, impacting availability. The high confidentiality and integrity impact ratings suggest that exploitation could potentially allow attackers to manipulate kernel memory or escalate privileges indirectly, though the requirement for physical access and user interaction limits remote exploitation. Organizations relying on Linux-based infrastructure in sectors such as manufacturing, telecommunications, automotive, or critical infrastructure could face operational disruptions if the vulnerability is exploited. The absence of known exploits reduces immediate threat but does not eliminate risk, especially in targeted attacks or insider threat scenarios.

Mitigation requires applying the official Linux kernel patches that address the driver_override freeing in rpmsg_remove(). Organizations should: 1) Identify all systems running affected Linux kernel versions, particularly those using rpmsg and virtio subsystems. 2) Prioritize patching embedded devices, industrial controllers, and specialized hardware that may not receive automatic updates. 3) Implement strict physical access controls to limit attacker proximity, as the attack vector requires physical presence. 4) Monitor kernel logs and system metrics for signs of memory leaks or unusual kworker activity that could indicate exploitation attempts. 5) Employ kernel integrity monitoring tools to detect unauthorized kernel modifications. 6) For environments where immediate patching is not feasible, consider disabling or restricting rpmsg usage if possible. 7) Maintain updated inventories of Linux kernel versions and ensure timely application of security updates from trusted sources.