CVE-2025-37973 is a vulnerability identified in the Linux kernel's Wi-Fi subsystem, specifically within the cfg80211 component responsible for wireless configuration. The flaw arises during the multi-link element (MLE) defragmentation process, which is part of handling fragmented information elements (IEs) in Wi-Fi management frames. The vulnerability is due to an incorrect calculation of the remaining IEs length after processing the multi-link element. Specifically, the multi-link element length is added to the total IEs length when calculating the length of remaining IEs, which can lead to an out-of-bounds memory access if the multi-link element or its fragments are the last elements in the IEs buffer. This out-of-bounds access could potentially result in memory corruption, leading to undefined behavior such as kernel crashes (denial of service) or possibly privilege escalation if exploited. The fix involves correctly calculating the remaining IEs length by deducting the multi-link element end offset from the total IEs end offset, thus preventing the out-of-bounds access. This vulnerability affects the Linux kernel versions identified by the commit hash 2481b5da9c6b2ee1fde55a1c29eb2ca377145a10 and likely other versions prior to the patch. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a risk primarily to systems running vulnerable Linux kernel versions with Wi-Fi capabilities, including servers, desktops, and embedded devices. Exploitation could lead to denial of service via kernel crashes or potentially allow attackers to execute arbitrary code with kernel privileges if they can craft malicious Wi-Fi frames exploiting the out-of-bounds access. This risk is particularly relevant for organizations relying on Linux-based infrastructure for critical operations, including telecommunications, manufacturing, and public services. The impact on confidentiality, integrity, and availability could be significant if exploited, as kernel-level compromise can lead to full system control. Additionally, devices in industrial control systems or IoT environments using Linux Wi-Fi stacks could be targeted, affecting operational continuity. However, exploitation requires proximity or network access to send crafted Wi-Fi frames, limiting the attack vector to local or wireless network attackers. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits following public disclosure.

European organizations should promptly identify and inventory all Linux systems with Wi-Fi capabilities running affected kernel versions. Applying the official Linux kernel patches that correct the multi-link element defragmentation logic is the primary mitigation step. Where immediate patching is not feasible, organizations should consider disabling Wi-Fi interfaces on critical systems or restricting Wi-Fi access to trusted networks only. Network segmentation and wireless intrusion detection systems (WIDS) can help monitor and block suspicious Wi-Fi management frames that could exploit this vulnerability. Additionally, organizations should ensure that kernel and system logs are monitored for unusual crashes or anomalies that might indicate exploitation attempts. For embedded and IoT devices, coordinate with vendors to obtain patched firmware or updates. Regularly updating Linux distributions and subscribing to security advisories will help maintain awareness and readiness against emerging exploits related to this vulnerability.