CVE-2025-20712 is a heap overflow vulnerability categorized under CWE-122, found in the WLAN Access Point (AP) driver of several MediaTek chipsets: MT6990, MT7990, MT7991, MT7992, and MT7993. The root cause is an incorrect bounds check in the driver code that allows an out-of-bounds write to heap memory. This flaw can be exploited remotely by an attacker in proximity (adjacent or within wireless range) to the vulnerable device, without requiring any user interaction or prior authentication. Successful exploitation leads to escalation of privileges, granting the attacker higher-level access to the device’s firmware or operating system. The vulnerability impacts SDK release 8.3.1.1 and earlier, including OpenWrt versions 21.02 and 23.05 for MT6990-based devices. The vulnerability affects confidentiality, integrity, and availability, as an attacker could execute arbitrary code or disrupt device operation. Although no public exploits are currently known, the CVSS v3.1 score of 8.8 (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) reflects the ease of exploitation and the critical impact. MediaTek has assigned Patch ID WCNCR00422323 and Issue ID MSV-3810 to address this issue, though no public patch links are currently available. This vulnerability is particularly concerning for embedded devices and wireless access points that rely on these chipsets, as it could lead to network compromise or lateral movement within enterprise environments.

For European organizations, the impact of CVE-2025-20712 is significant due to the widespread use of MediaTek chipsets in wireless access points, routers, and IoT devices. Exploitation could allow attackers to gain elevated privileges on network infrastructure devices, potentially leading to interception or manipulation of network traffic, deployment of persistent malware, or denial of service conditions. This could compromise sensitive data confidentiality, disrupt business operations, and facilitate further attacks within corporate networks. Critical sectors such as telecommunications, finance, healthcare, and government agencies that rely on secure wireless communications are particularly at risk. The proximity-based attack vector means attackers need to be physically near the target, but this is feasible in many urban and office environments. The lack of required user interaction or authentication lowers the barrier for exploitation, increasing the threat level. Additionally, the vulnerability affects OpenWrt-based devices, which are popular in custom and enterprise networking solutions across Europe, further broadening the potential impact.

European organizations should implement a multi-layered mitigation strategy. First, they must monitor MediaTek and device vendors for official patches corresponding to Patch ID WCNCR00422323 and apply them promptly once available. Until patches are deployed, network administrators should segment wireless networks to isolate vulnerable devices and restrict access to critical infrastructure. Employ wireless intrusion detection/prevention systems (WIDS/WIPS) to detect anomalous or unauthorized wireless activity indicative of exploitation attempts. Disable or limit wireless AP features that are not essential to reduce the attack surface. Regularly audit and update firmware on all devices using affected chipsets, including those running OpenWrt. Network access controls and strong encryption protocols should be enforced to reduce the risk of unauthorized proximity attacks. Additionally, organizations should conduct penetration testing and vulnerability assessments focused on wireless infrastructure to identify and remediate exposures. Finally, maintain comprehensive logging and monitoring to detect suspicious behavior early and respond swiftly to incidents.