CVE-2025-20712 is a heap overflow vulnerability classified under CWE-122, found in the WLAN Access Point (AP) driver of several MediaTek chipsets: MT6990, MT7990, MT7991, MT7992, and MT7993. The vulnerability stems from an incorrect bounds check in the driver code, which leads to an out-of-bounds write on the heap memory. This memory corruption can be exploited remotely by an attacker located in proximity to the affected device, such as within wireless signal range, without requiring any user interaction or additional execution privileges. The flaw allows for escalation of privilege on the device, potentially enabling the attacker to execute arbitrary code or disrupt normal device operation. The affected software versions include SDK release 8.3.1.1 and earlier, as well as OpenWrt versions 21.02 and 23.05 for the MT6990 chipset. Although no public exploits have been reported yet, the vulnerability poses a significant risk due to the ease of exploitation and the critical role of these chipsets in wireless networking equipment. The issue was reserved in November 2024 and published in October 2025, with a patch ID WCNCR00422323 and issue ID MSV-3810 referenced by MediaTek. The absence of a CVSS score requires an independent severity assessment based on the technical details and potential impact.

For European organizations, this vulnerability could have severe consequences, especially for enterprises and service providers relying on MediaTek chipset-based wireless access points and routers. Successful exploitation could lead to unauthorized privilege escalation, allowing attackers to manipulate device configurations, intercept or disrupt wireless communications, or deploy persistent malware within network infrastructure. This threatens the confidentiality and integrity of sensitive data transmitted over affected wireless networks and could cause denial of service conditions, impacting availability. Critical sectors such as finance, healthcare, government, and telecommunications that depend on secure and reliable wireless connectivity are particularly vulnerable. The proximity-based attack vector means that attackers need physical closeness, which may limit remote exploitation but does not eliminate risk in densely populated or publicly accessible environments. The lack of user interaction requirement increases the risk of automated or stealthy attacks. Overall, the vulnerability could undermine trust in wireless infrastructure and lead to significant operational and reputational damage.

European organizations should immediately inventory their wireless infrastructure to identify devices using the affected MediaTek chipsets and software versions. They should monitor MediaTek and OpenWrt official channels for patches corresponding to patch ID WCNCR00422323 and apply updates promptly once available. Until patches are deployed, organizations should implement network segmentation to isolate vulnerable wireless devices from critical systems and sensitive data. Employing wireless intrusion detection and prevention systems (WIDS/WIPS) can help detect anomalous activities indicative of exploitation attempts. Physical security controls should be enhanced to limit attacker proximity to wireless access points, especially in public or semi-public areas. Network administrators should disable unnecessary wireless services or features that could be exploited and enforce strong authentication and encryption protocols to reduce attack surface. Regular firmware audits and vulnerability scanning focused on wireless infrastructure are recommended to identify and remediate similar issues proactively. Additionally, organizations should prepare incident response plans tailored to wireless infrastructure compromise scenarios.