CVE-2023-52477 is a vulnerability identified in the Linux kernel's USB hub driver code, specifically within the handling of BOS (Binary Object Store) descriptors in the usb/core/hub.c and usb/core/hub.h files. The issue arises because multiple functions access the udev->bos field without verifying whether it has been properly allocated and initialized. If the function usb_get_bos_descriptor() fails, udev->bos remains NULL. Subsequent dereferencing of this NULL pointer leads to a kernel NULL pointer dereference, causing a system crash (kernel panic). The vulnerability manifests as a denial-of-service condition due to the kernel crash triggered by USB hub events, such as port resets. The problem is rooted in insufficient defensive programming when handling USB device descriptors, leading to stability issues when encountering certain USB devices or conditions that cause usb_get_bos_descriptor() to fail. The fix involves adding checks to fall back to default behavior if the BOS descriptor is inaccessible, skipping dependent functionalities like Link Power Management (LPM) support checks, SuperSpeed capability checks, and U1/U2 state setups, thereby preventing the NULL pointer dereference and system crash. This vulnerability affects Linux kernel versions prior to the patch and is relevant to systems using affected kernel versions with USB hub support. No known exploits are reported in the wild at this time, and no CVSS score has been assigned yet.

For European organizations, the primary impact of CVE-2023-52477 is the potential for denial-of-service (DoS) conditions on Linux-based systems due to kernel crashes triggered by USB device interactions. This can affect servers, workstations, embedded devices, and IoT systems running vulnerable Linux kernels. The disruption could lead to system downtime, loss of availability of critical services, and operational interruptions. In environments with high USB device usage or where USB hubs are common (e.g., office desktops, industrial control systems, or data centers with USB peripherals), the risk is more pronounced. Although this vulnerability does not directly lead to privilege escalation or data compromise, the forced reboots and instability could be exploited as part of a broader attack strategy to disrupt business continuity. For sectors such as finance, healthcare, manufacturing, and public administration in Europe, where Linux servers and devices are widely deployed, this vulnerability could impact service reliability and compliance with availability requirements. Additionally, organizations with strict uptime SLAs or those relying on Linux-based embedded systems in critical infrastructure should prioritize mitigation to avoid unexpected outages.

To mitigate CVE-2023-52477, European organizations should: 1) Apply the latest Linux kernel patches that address this vulnerability as soon as they become available from their Linux distribution vendors or upstream kernel sources. 2) Audit and update all Linux systems, including servers, desktops, embedded devices, and IoT endpoints, to ensure they run patched kernel versions. 3) Implement USB device control policies to restrict or monitor USB device usage, especially in sensitive environments, to reduce exposure to potentially malformed or malicious USB devices that could trigger the bug. 4) Employ kernel crash monitoring and automated recovery mechanisms to minimize downtime in case of unexpected crashes. 5) For critical systems where immediate patching is not feasible, consider disabling USB hub support or limiting USB device connections temporarily as a short-term workaround. 6) Maintain robust incident response and system backup procedures to recover quickly from any service disruptions caused by this vulnerability. 7) Engage with Linux distribution security advisories and subscribe to vulnerability notifications to stay informed about patch releases and related security updates.