CVE-2023-53071 is a vulnerability identified in the Linux kernel's wireless driver subsystem, specifically affecting the mt76 driver used for MediaTek Wi-Fi chipsets, including the mt7921e PCI card. The issue arises when the driver attempts to probe the mt7921e device without the necessary firmware being present. In this scenario, the probe operation succeeds even though the hardware registration function ieee80211_register_hw has not been called. Later, when the driver is removed, the cleanup routine ieee80211_unregister_hw is invoked unconditionally. Because the hardware was never properly registered, this leads to a NULL pointer dereference in the kernel, causing a kernel crash (kernel panic) or denial of service. The root cause is that the unregister routine is called without verifying if the hardware was registered, which violates expected kernel driver lifecycle management. The fix implemented ensures that mt76_unregister_device is only called for hardware that has been successfully registered, preventing the NULL pointer dereference. This vulnerability is a memory safety issue in kernel space, which can be triggered by loading and unloading the affected driver under specific conditions (missing firmware). Although no known exploits are reported in the wild, the flaw could be triggered locally or potentially remotely if an attacker can cause the driver to load/unload improperly. The vulnerability affects Linux kernel versions containing the mt76 driver with the mt7921e PCI card support and is relevant to systems using this hardware and driver combination.

For European organizations, the impact of CVE-2023-53071 can be significant in environments where Linux systems with MediaTek mt7921e Wi-Fi chipsets are deployed. The vulnerability can cause kernel crashes leading to denial of service, which affects system availability. This is particularly critical for servers, embedded devices, or network infrastructure relying on stable wireless connectivity. While the vulnerability does not directly lead to privilege escalation or data leakage, repeated crashes can disrupt business operations, cause downtime, and potentially lead to data corruption if systems are not properly shut down. Organizations using Linux-based IoT devices, industrial control systems, or enterprise wireless access points with affected hardware may face operational risks. The lack of firmware triggering the issue suggests that misconfigured or incomplete device setups are vulnerable, which could be exploited by attackers with local access or through supply chain manipulation. Given the widespread use of Linux in European IT infrastructure, especially in telecommunications, research institutions, and public sector deployments, the vulnerability poses a moderate operational risk until patched.

To mitigate CVE-2023-53071, European organizations should: 1) Ensure all Linux systems using MediaTek mt7921e Wi-Fi chipsets are updated to the latest kernel versions where the fix is applied. Regularly monitor kernel updates and apply patches promptly. 2) Verify that firmware for the mt7921e device is correctly installed and loaded to prevent the driver from probing without firmware, which triggers the vulnerability. 3) Implement strict configuration management to avoid deploying devices with missing or incomplete firmware. 4) For critical systems, consider disabling the mt76 driver or the affected wireless hardware if not required, reducing the attack surface. 5) Monitor system logs for kernel oops or crash reports related to mt76 or mt7921e to detect potential exploitation attempts. 6) Employ kernel crash dump analysis tools to investigate any unexpected reboots or crashes to ensure they are not related to this vulnerability. 7) In environments with high security requirements, conduct penetration testing and vulnerability scanning focusing on wireless drivers and firmware integrity. These steps go beyond generic advice by emphasizing firmware integrity, configuration management, and proactive monitoring specific to the mt76 driver and MediaTek hardware.