CVE-2023-52907 is a use-after-free vulnerability identified in the Linux kernel's NFC (Near Field Communication) subsystem, specifically within the pn533 driver that handles USB communication with PN533 NFC controllers. The flaw arises in the function pn533_usb_send_frame(), where the code fails to properly wait for the completion of the out_urb (outbound USB request block) before sending the in_urb (inbound USB request block). The out_urb's callback frees the socket buffer (skb) data used as the transfer buffer for out_urb, but if the in_urb completes earlier, it may access this freed memory, leading to a use-after-free condition. This can cause memory corruption, kernel crashes, or potentially allow an attacker to execute arbitrary code in kernel space. The vulnerability was discovered using a modified syzkaller fuzzer and is related to a race condition in USB gadget driver code, as indicated by the KASAN (Kernel Address Sanitizer) report and call trace involving dummy_hcd and timer functions. The fix involves restructuring the callbacks to ensure that the in_urb is not sent until the out_urb's callback has completed, effectively preventing premature access to freed memory. This vulnerability affects Linux kernel versions identified by the commit hash c46ee38620a2aa2b25b16bc9738ace80dbff76a4 and likely other versions containing the same code pattern. No known exploits are reported in the wild as of the publication date (August 21, 2024), and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a risk primarily to systems running Linux kernels with NFC functionality enabled and using the pn533 USB driver, which is common in embedded devices, IoT equipment, and some industrial control systems. Exploitation could lead to kernel crashes causing denial of service or, in worst cases, privilege escalation allowing attackers to gain kernel-level code execution. This could compromise the confidentiality and integrity of sensitive data and disrupt critical services. Organizations relying on NFC-enabled Linux devices for secure access control, payment systems, or industrial automation could be particularly impacted. The lack of known exploits suggests a low immediate threat, but the potential severity of kernel-level vulnerabilities necessitates prompt patching. The vulnerability's exploitation requires local access or the ability to interact with the vulnerable NFC device, limiting remote attack vectors but still posing a risk in environments where untrusted users or malicious insiders have physical or logical access.

European organizations should prioritize updating Linux kernels to versions that include the patch for CVE-2023-52907 once available. Until patches are applied, organizations should consider disabling NFC functionality or the pn533 driver on systems where it is not essential. For devices that must use NFC, implement strict access controls to limit who can interact with NFC hardware. Monitoring kernel logs for unusual USB or NFC-related errors may help detect exploitation attempts. Additionally, employing kernel hardening techniques such as Kernel Address Sanitizer (KASAN) in testing environments can help identify similar issues proactively. Organizations should also review and restrict physical and logical access to NFC-enabled devices to reduce the risk of local exploitation. Coordination with device vendors to ensure timely firmware and kernel updates is critical, especially for embedded and IoT devices deployed in operational technology environments.