CVE-2023-53049 is a vulnerability identified in the Linux kernel's USB Component, specifically within the USB Type-C Connector System Software Interface (UCSI) driver. The issue arises in the function ucsi_connector_change(), which dereferences a NULL pointer under certain failure conditions. When the ucsi_init() function fails, the ucsi->connector pointer remains NULL. However, if the system is using the ucsi_acpi implementation, events may still be generated that cause ucsi_connector_change() to be invoked. This function attempts to dereference the ucsi->connector pointer without verifying its validity, leading to a NULL pointer dereference. The root cause is that the notification mask (ucsi->ntfy) is set inside ucsi_init() before the initialization has fully succeeded, allowing event handling code to proceed erroneously. The fix involves deferring the setting of ucsi->ntfy until after successful initialization, preventing the processing of connector change events when the connector pointer is NULL. This vulnerability can cause a kernel crash (denial of service) due to the NULL pointer dereference. There is no indication that this vulnerability allows privilege escalation or arbitrary code execution. No known exploits are currently reported in the wild. The affected versions are specific Linux kernel commits identified by their hashes, indicating this is a recent and targeted fix. No CVSS score has been assigned yet, and no patch links are provided in the data, but the vulnerability is published and acknowledged by the Linux project.

For European organizations, the primary impact of CVE-2023-53049 is a potential denial of service (DoS) on systems running affected Linux kernel versions with USB Type-C support via UCSI, especially those relying on the ACPI implementation. This could lead to system instability or crashes triggered by USB events, potentially disrupting critical services or operations. Organizations with infrastructure that depends on Linux servers, embedded devices, or workstations using USB Type-C ports may experience interruptions. While this vulnerability does not appear to allow remote code execution or privilege escalation, the resulting kernel panic could be exploited by local users or malicious USB devices to cause service outages. This is particularly relevant for environments with high USB device turnover or automated USB device management. The impact is more significant in sectors where uptime and system availability are critical, such as finance, healthcare, manufacturing, and public services. Given the widespread use of Linux in European data centers, cloud providers, and enterprise environments, unpatched systems could face operational risks. However, the lack of known exploits and the requirement for specific conditions to trigger the vulnerability somewhat limit immediate widespread impact.

European organizations should prioritize updating their Linux kernels to versions that include the fix for CVE-2023-53049 as soon as patches become available. Until patches are applied, organizations can mitigate risk by limiting or controlling USB device usage, especially Type-C devices, on critical systems. Implementing strict USB device whitelisting and disabling unused USB ports can reduce exposure. Monitoring kernel logs for unusual USB-related errors or crashes may help detect attempts to trigger this vulnerability. For environments using ACPI-based UCSI implementations, consider disabling UCSI notifications if feasible, or applying kernel boot parameters to limit USB event handling. Additionally, organizations should ensure robust endpoint security policies and user training to prevent insertion of unauthorized USB devices. Regularly auditing Linux kernel versions across infrastructure and embedded devices will help identify vulnerable systems. Coordination with Linux distribution vendors for timely patch deployment is essential. Finally, maintaining backups and high availability configurations can minimize operational impact in case of DoS incidents.