CVE-2025-20732 is a stack overflow vulnerability classified under CWE-121 found in the WLAN Access Point (AP) driver of several MediaTek chipsets (MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, MT7986). The root cause is an incorrect bounds check in the driver code, which leads to an out-of-bounds write operation on the stack. This memory corruption can be exploited to escalate privileges locally on the device. However, exploitation requires that the attacker already has System-level privileges, and the vulnerability is only exploitable when the OceReducedNeighborReport feature is disabled. No user interaction is needed, making it a purely local privilege escalation vector. The affected software versions include SDK release 7.6.7.2 and earlier, and openWRT versions 19.07 and 21.02, which are commonly used in embedded wireless devices and routers. The vulnerability has a CVSS 3.1 score of 5.3, indicating medium severity with low to medium impact on confidentiality, integrity, and availability. No public exploits have been reported yet, but the presence of a patch (WCNCR00441510) indicates vendor awareness and remediation availability. This vulnerability could allow an attacker with some system privileges to gain higher privileges, potentially compromising device security and stability.

For European organizations, this vulnerability poses a risk primarily to wireless infrastructure devices that incorporate the affected MediaTek chipsets and run vulnerable SDK or openWRT versions. Successful exploitation could allow an attacker with local system privileges to escalate to higher privileges, potentially enabling unauthorized configuration changes, installation of persistent malware, or disruption of wireless services. This could impact network availability and integrity, especially in environments relying on embedded devices for critical communications such as enterprise networks, public Wi-Fi, and industrial control systems. The lack of user interaction requirement increases the risk in scenarios where attackers have limited access but can execute local code. While confidentiality impact is limited, integrity and availability could be significantly affected if exploited. The medium CVSS score reflects moderate risk, but the threat is heightened in sensitive or high-value environments. Organizations with wireless infrastructure based on MediaTek chipsets should assess exposure and prioritize patching to mitigate potential privilege escalation and maintain network security.

To mitigate CVE-2025-20732, European organizations should: 1) Identify all devices using MediaTek chipsets MT6890, MT7615, MT7622, MT7663, MT7915, MT7916, MT7981, and MT7986, especially those running SDK release 7.6.7.2 or earlier and openWRT versions 19.07 and 21.02. 2) Apply the vendor-provided patch WCNCR00441510 as soon as it becomes available and tested. 3) If patching is delayed, consider disabling the affected feature OceReducedNeighborReport if feasible, as its enabled state influences exploitability. 4) Restrict local system-level access to trusted personnel and enforce strict access controls to minimize the risk of local privilege escalation. 5) Monitor device logs and behavior for signs of exploitation attempts or anomalous privilege escalations. 6) Maintain updated inventories of embedded devices and ensure firmware/software is regularly updated. 7) Employ network segmentation to isolate vulnerable devices and limit lateral movement in case of compromise. 8) Engage with vendors and suppliers to confirm patch availability and deployment timelines. These targeted actions go beyond generic advice by focusing on the specific affected components, feature flags, and operational controls relevant to this vulnerability.