CVE-2023-52502 is a medium-severity vulnerability identified in the Linux kernel's NFC (Near Field Communication) subsystem, specifically within the Logical Link Control Protocol (LLCP) socket handling code. The vulnerability arises due to race conditions in the functions nfc_llcp_sock_get() and nfc_llcp_sock_get_sn(), which are responsible for retrieving references to NFC LLCP sockets. The root cause is that the code releases a lock before safely obtaining a reference to the socket, leading to a use-after-free (UAF) condition. This means that after the lock is released, the socket object could be freed or modified by another thread, causing the original thread to operate on invalid memory. Additionally, the function nfc_llcp_recv_snl() was found to not properly ensure that the socket retrieved by nfc_llcp_sock_from_sn() remains valid during its use, compounding the risk of UAF. Exploiting this vulnerability could allow a local attacker with low privileges to cause a denial of service (kernel crash) due to memory corruption or potentially escalate privileges if the UAF is leveraged for arbitrary code execution. The CVSS 3.1 score of 6.3 reflects a medium severity with local attack vector, high attack complexity, low privileges required, no user interaction, and high confidentiality impact but no integrity impact. No known exploits are currently reported in the wild. The vulnerability affects specific Linux kernel versions identified by commit hashes, indicating that it is present in certain recent kernel builds prior to patching. The fix involves ensuring that references to sockets are acquired before releasing locks to prevent the race condition and subsequent UAF.

For European organizations, the impact of CVE-2023-52502 depends largely on their use of Linux systems with NFC capabilities. Many enterprises and government agencies use Linux servers and endpoints, but NFC functionality is more common in embedded devices, IoT systems, and mobile or specialized hardware. If such devices run vulnerable Linux kernels, attackers with local access could exploit this flaw to cause system crashes or potentially escalate privileges, leading to disruption of services or unauthorized access. In critical infrastructure sectors like transportation, healthcare, or manufacturing, where NFC-enabled devices may be used for access control or data exchange, exploitation could lead to operational downtime or data confidentiality breaches. However, since exploitation requires local access and the attack complexity is high, remote exploitation is unlikely. The confidentiality impact is high, meaning sensitive data handled by NFC sockets could be exposed. Overall, organizations relying on Linux-based NFC implementations should consider this vulnerability a moderate risk, especially if devices are accessible to untrusted users or attackers.

To mitigate CVE-2023-52502, organizations should promptly apply the official Linux kernel patches that address the race conditions in the NFC LLCP socket handling code. Since the vulnerability is in the kernel, updating to a fixed kernel version is the most effective measure. For environments where immediate patching is not feasible, consider disabling NFC functionality on Linux systems if it is not required, thereby eliminating the attack surface. Additionally, enforce strict local access controls and user privilege restrictions to prevent untrusted users from interacting with NFC subsystems. Monitoring kernel logs for unusual NFC-related errors or crashes can help detect attempted exploitation. For embedded or IoT devices, coordinate with vendors to obtain patched firmware or kernel updates. Finally, incorporate this vulnerability into vulnerability management and patching workflows to ensure timely remediation across all affected Linux systems.