CVE-2025-20682 is a security vulnerability identified in several MediaTek wireless chipset models, including MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, and MT7986. The flaw exists in the WLAN Access Point (AP) driver, where an incorrect bounds check leads to an out-of-bounds write condition (classified under CWE-787). This type of vulnerability occurs when the software writes data outside the boundaries of allocated memory buffers, potentially corrupting adjacent memory. Exploitation of this vulnerability requires local user privileges but does not require user interaction, meaning an attacker with user-level execution rights on the device can trigger the flaw without additional input from other users. The consequence of this out-of-bounds write is a local escalation of privilege, allowing an attacker to gain higher-level privileges on the affected device. The affected software versions include SDK release 7.6.7.2 and earlier, as well as openWRT versions 19.07 and 21.02 that utilize these chipsets. No CVSS score has been assigned yet, and there are no known exploits in the wild at the time of publication. The vulnerability was publicly disclosed on July 8, 2025, with MediaTek as the assigner. Due to the nature of the flaw, it poses a significant risk to devices running these chipsets, especially embedded systems and network equipment that rely on MediaTek WLAN drivers. The lack of user interaction requirement increases the risk of automated or stealthy exploitation by malicious local users or malware already present on the device. The absence of a patch link suggests that remediation may require vendor firmware updates or openWRT community patches, which should be prioritized once available.

For European organizations, this vulnerability presents a considerable risk, particularly for enterprises and service providers using network equipment or embedded devices powered by the affected MediaTek chipsets. The ability for a local user to escalate privileges without user interaction could allow attackers to compromise critical network infrastructure components such as wireless access points, routers, or IoT devices. This could lead to unauthorized access to sensitive network segments, interception or manipulation of network traffic, and potential lateral movement within corporate networks. Given the widespread use of openWRT in custom and commercial networking devices across Europe, organizations relying on these platforms may face increased exposure. The impact extends to confidentiality, as attackers could access sensitive data; integrity, through potential manipulation of network communications; and availability, if the vulnerability is leveraged to disrupt device operation. The local nature of the exploit means that initial compromise or insider threats are prerequisites, but once foothold is gained, the escalation can facilitate broader attacks. This is particularly concerning for sectors with stringent security requirements such as finance, healthcare, and critical infrastructure within Europe.

To mitigate this vulnerability effectively, European organizations should: 1) Identify all devices using the affected MediaTek chipsets and verify firmware versions against the vulnerable SDK and openWRT releases. 2) Monitor MediaTek and openWRT official channels for patches or firmware updates addressing CVE-2025-20682 and apply them promptly. 3) Where immediate patching is not possible, implement strict access controls to limit local user privileges on affected devices, minimizing the risk of exploitation. 4) Employ network segmentation to isolate vulnerable devices from critical infrastructure and sensitive data repositories. 5) Use host-based intrusion detection systems (HIDS) and endpoint protection solutions capable of detecting anomalous behavior indicative of privilege escalation attempts. 6) Regularly audit device configurations and user accounts to ensure no unauthorized local access exists. 7) For openWRT deployments, consider upgrading to newer supported versions beyond 21.02 once patches are available or apply community-provided security patches. 8) Educate IT staff and users about the risks of local privilege escalation vulnerabilities and enforce strong physical and logical security controls to prevent unauthorized device access.