CVE-2023-37453 is a medium-severity vulnerability identified in the USB subsystem of the Linux kernel up to version 6.4.2. The flaw exists in the read_descriptors function within the drivers/usb/core/sysfs.c source file. Specifically, it is an out-of-bounds read issue (CWE-125) that can cause the kernel to crash. This vulnerability arises when the USB subsystem improperly handles USB device descriptors, leading to an out-of-bounds memory access. The consequence of this flaw is a denial-of-service (DoS) condition due to kernel crash, impacting system availability. The CVSS v3.1 score is 4.6, reflecting a medium severity with the vector AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, meaning the attack requires physical access (local network or physical proximity), low attack complexity, no privileges or user interaction needed, and only impacts availability without affecting confidentiality or integrity. No known exploits are currently reported in the wild, and no vendor or product-specific details are provided beyond the Linux kernel USB subsystem. The vulnerability is relevant to all Linux systems running affected kernel versions that support USB devices, as the USB subsystem is a core component handling device enumeration and communication. Exploitation would require an attacker to connect a malicious USB device or otherwise interact with the USB subsystem physically or through a local network vector that can trigger the out-of-bounds read. The impact is primarily a system crash, which could disrupt operations, especially on critical infrastructure or servers relying on Linux kernels with vulnerable versions. The lack of a patch link suggests that remediation may require updating to a kernel version beyond 6.4.2 once a fix is released or applying vendor-specific patches.

For European organizations, this vulnerability poses a risk primarily to availability. Systems running vulnerable Linux kernels with USB support could be crashed by an attacker with physical access or local network access capable of triggering the flaw. This could disrupt business operations, especially in environments where Linux servers or workstations are critical, such as in industrial control systems, telecommunications, finance, or public sector infrastructure. The impact is less severe on confidentiality and integrity, but denial-of-service conditions can cause operational downtime, loss of productivity, and potential cascading effects in interconnected systems. Organizations with strict uptime requirements or those operating in sectors with high availability demands (e.g., healthcare, transportation) may face significant operational risks. Additionally, the requirement for physical or local access limits remote exploitation but does not eliminate risk in environments with shared physical access or where USB devices are frequently connected. The vulnerability could also be exploited in targeted attacks or insider threat scenarios. Given the widespread use of Linux in European enterprises and public institutions, the vulnerability's impact is non-negligible, especially if unpatched systems are present in critical infrastructure or sensitive environments.

To mitigate CVE-2023-37453, European organizations should: 1) Monitor for and apply Linux kernel updates promptly once patches addressing this vulnerability are released, ideally upgrading beyond kernel version 6.4.2. 2) Implement strict physical security controls to limit unauthorized access to systems and prevent connection of untrusted USB devices. 3) Employ USB device control policies using endpoint security solutions or kernel-level USB filtering to restrict or whitelist USB devices allowed to connect. 4) Use kernel lockdown features or security modules (e.g., SELinux, AppArmor) to reduce the attack surface of the USB subsystem. 5) Conduct regular audits of Linux kernel versions in use across the organization to identify vulnerable systems. 6) Educate staff about the risks of connecting unknown USB devices and enforce policies to prevent unauthorized device usage. 7) Where possible, isolate critical Linux systems from networks or environments where physical access is not tightly controlled. These measures go beyond generic patching advice by emphasizing physical security, device control, and proactive system inventory management.