CVE-2024-53213 is a vulnerability identified in the Linux kernel's USB network driver for the LAN78xx family of USB Ethernet adapters. The issue arises from a double free bug in the interrupt buffer allocation and deallocation sequence within the lan78xx_probe() function. Specifically, the buffer 'buf' was freed twice: once implicitly when usb_free_urb(dev->urb_intr) was called with the URB_FREE_BUFFER flag, and a second time explicitly via kfree(buf). This double free can lead to undefined behavior including potential kernel memory corruption, crashes, or exploitation opportunities. The root cause was improper ordering of memory allocation and deallocation calls. The fix involved reordering the kmalloc() and usb_alloc_urb() calls to ensure that the buffer is allocated only after the urb is allocated, allowing usb_fill_int_urb() to manage the buffer lifecycle correctly and removing the redundant explicit free. This correction prevents the double free condition and stabilizes the memory management in the driver. The vulnerability affects Linux kernel versions containing the faulty commit identified by the hash a6df95cae40bee555e01a37b4023ce8e97ffa249. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability could have significant implications depending on their use of Linux systems with LAN78xx USB Ethernet adapters. Exploitation of a double free vulnerability in kernel space can lead to system crashes (denial of service) or potentially privilege escalation if an attacker can manipulate kernel memory. This could compromise the confidentiality, integrity, and availability of affected systems. Organizations relying on Linux-based network infrastructure, embedded devices, or endpoint systems using these USB network adapters could face operational disruptions or security breaches. Given the widespread use of Linux in European enterprises, government agencies, and critical infrastructure, the vulnerability poses a moderate risk, especially in environments where physical or local access to USB ports is possible. However, remote exploitation likelihood is low unless combined with other vulnerabilities or attack vectors. The absence of known exploits reduces immediate risk but does not eliminate the need for timely patching.

European organizations should prioritize updating their Linux kernels to versions where this vulnerability is patched. Specifically, they should track kernel updates that reorder the kmalloc() and usb_alloc_urb() calls in the lan78xx driver and remove the redundant kfree(buf). Beyond patching, organizations should implement strict USB device control policies to limit unauthorized USB device connections, reducing attack surface. Monitoring kernel logs for unusual USB-related errors or crashes can help detect exploitation attempts. For critical systems, consider disabling unused USB network adapters or restricting their use to trusted devices only. Additionally, employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and Control Flow Integrity (CFI) can reduce exploitation success. Regular vulnerability scanning and inventory of USB devices in use will aid in identifying affected systems promptly.