CVE-2025-20716 is a vulnerability classified under CWE-787 (Out-of-bounds Write) found in the WLAN Access Point (AP) driver of multiple MediaTek chipsets, including MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, and MT7986. The root cause is an incorrect bounds check in the driver code, which allows an out-of-bounds write operation. This memory corruption flaw can be leveraged by an attacker who already possesses System-level privileges on the device to escalate their privileges further, potentially gaining higher control over the system. The vulnerability does not require any user interaction, making it easier to exploit once initial access is obtained. Affected versions include SDK release 7.6.7.2 and earlier, as well as openWRT versions 19.07 and 21.02 for the MT6890 chipset. Although no public exploits have been reported yet, the vulnerability poses a significant risk due to its potential to undermine system integrity and security. The flaw is particularly concerning in embedded devices and wireless infrastructure that rely on these chipsets, as an attacker could leverage it to bypass security controls and execute arbitrary code or disrupt device operation. MediaTek has assigned the patch ID WCNCR00421149 and issue ID MSV-3728 to this vulnerability, indicating that a fix is in development or available through vendor channels. The vulnerability was reserved in November 2024 and published in October 2025, reflecting a recent disclosure. Given the widespread use of MediaTek chipsets in consumer and enterprise wireless devices, this vulnerability demands attention from security teams managing affected hardware.

For European organizations, the impact of CVE-2025-20716 can be significant, especially for those relying on MediaTek-based wireless access points, routers, and IoT devices. Successful exploitation could allow attackers with local System privileges to escalate their access, potentially leading to full device compromise. This can result in unauthorized control over network infrastructure, interception or manipulation of network traffic, and disruption of wireless services. Critical sectors such as telecommunications, manufacturing, healthcare, and smart city infrastructure that deploy MediaTek chipset-based devices could face operational disruptions and data breaches. The vulnerability undermines device integrity and could facilitate lateral movement within networks. Since the flaw requires prior System-level access, the initial compromise vector might be through other vulnerabilities or insider threats, but once exploited, it can severely limit the effectiveness of existing security controls. The absence of user interaction for exploitation increases the risk of automated or stealthy attacks. Additionally, the vulnerability could affect supply chain security if devices are widely deployed without timely patching. Overall, the threat could degrade trust in wireless infrastructure and increase incident response costs for European entities.

To mitigate CVE-2025-20716, European organizations should: 1) Immediately inventory devices using affected MediaTek chipsets and verify firmware versions against the vulnerable SDK releases and openWRT versions. 2) Apply vendor-supplied patches or firmware updates as soon as they become available, referencing MediaTek patch ID WCNCR00421149. 3) Restrict local administrative access to devices to trusted personnel only, minimizing the risk of attackers obtaining System privileges. 4) Implement strict network segmentation to limit the impact of any local compromise and prevent lateral movement. 5) Monitor device logs and network traffic for unusual activities indicative of privilege escalation attempts or memory corruption exploitation. 6) Employ endpoint detection and response (EDR) solutions on management systems interfacing with affected devices to detect suspicious behavior. 7) For openWRT-based devices, upgrade to versions beyond 21.02 or apply community patches addressing this vulnerability. 8) Conduct regular security audits and penetration tests focusing on wireless infrastructure to identify potential exploitation paths. 9) Educate IT staff about the vulnerability specifics to ensure rapid response and patch management. 10) Consider deploying additional security controls such as application whitelisting and integrity monitoring on critical devices.