CVE-2025-20728 is a heap overflow vulnerability identified in the WLAN STA driver of several MediaTek wireless chipsets, specifically the MT7902, MT7920, MT7921, MT7922, MT7925, and MT7927 models. The root cause is an incorrect bounds check that allows an out-of-bounds write operation on the heap memory. This vulnerability falls under CWE-122 (Heap-based Buffer Overflow). Exploitation requires the attacker to have local user execution privileges but does not require any user interaction, meaning an attacker with local access can trigger the flaw without additional input from the victim. The vulnerability can lead to local escalation of privilege by corrupting heap memory, potentially allowing arbitrary code execution or system compromise with elevated privileges. The affected software versions include NB SDK release 3.7 and earlier. Although no public exploits have been reported, the nature of the vulnerability and the affected widely deployed MediaTek chipsets pose a significant risk. The vulnerability was reserved in November 2024 and published in November 2025, but no CVSS score has been assigned yet. The lack of a patch link suggests that remediation may be pending or distributed through vendor-specific channels. Given the critical role of wireless connectivity in many devices, this vulnerability could impact a broad range of endpoints, including laptops, IoT devices, and embedded systems that utilize these chipsets. The vulnerability's exploitation could compromise device confidentiality, integrity, and availability by allowing attackers to gain elevated privileges locally.

For European organizations, the impact of CVE-2025-20728 can be substantial, especially in sectors relying heavily on wireless connectivity such as telecommunications, manufacturing, healthcare, and critical infrastructure. The vulnerability enables local attackers to escalate privileges, potentially allowing them to bypass security controls, access sensitive data, or disrupt system operations. This is particularly concerning for devices deployed in enterprise environments, IoT ecosystems, and embedded systems where MediaTek chipsets are prevalent. The absence of required user interaction lowers the barrier for exploitation once local access is obtained, increasing the risk from insider threats or attackers who gain initial foothold through other means. Compromise of wireless drivers can also undermine network security, facilitating further lateral movement or persistent access. European organizations with large deployments of laptops, mobile devices, or IoT devices using these chipsets may face increased risk of targeted attacks or malware leveraging this vulnerability. Additionally, critical infrastructure operators in Europe could experience operational disruptions or data breaches if attackers exploit this flaw to gain control over networked devices. The overall impact includes potential loss of confidentiality, integrity, and availability of affected systems, with possible cascading effects on organizational security posture and regulatory compliance.

1. Apply patches or firmware updates provided by MediaTek or device manufacturers as soon as they become available to address the vulnerability in the affected WLAN STA drivers. 2. In the absence of patches, restrict local user privileges and enforce strict access controls to limit the ability of untrusted users to execute code or access vulnerable devices. 3. Employ endpoint detection and response (EDR) solutions to monitor for anomalous local activity indicative of exploitation attempts, such as unusual memory operations or privilege escalation behaviors. 4. Conduct regular inventory and asset management to identify devices using the affected MediaTek chipsets and prioritize them for remediation. 5. Implement network segmentation to isolate critical systems and reduce the impact of potential compromises originating from vulnerable devices. 6. Educate users and administrators about the risks of local privilege escalation vulnerabilities and the importance of maintaining updated device firmware and drivers. 7. Collaborate with vendors and security communities to stay informed about patch releases and emerging exploit techniques related to this vulnerability. 8. Consider deploying host-based intrusion prevention systems (HIPS) that can detect and block heap overflow exploitation attempts targeting WLAN drivers. 9. For IoT and embedded devices, evaluate the feasibility of firmware updates or device replacement if patches are unavailable or unsupported. 10. Integrate this vulnerability into organizational risk assessments and incident response plans to ensure preparedness for potential exploitation scenarios.