CVE-2025-20672 is a critical heap overflow vulnerability (CWE-122) found in the Bluetooth drivers of several MediaTek wireless chipsets, specifically the MT7902, MT7921, MT7922, MT7925, and MT7927 models. The flaw arises from an incorrect bounds check in the Bluetooth driver's handling of data, which leads to an out-of-bounds write on the heap. This memory corruption vulnerability can be exploited locally by an attacker with user-level execution privileges to escalate their privileges on the affected system. Notably, exploitation does not require any user interaction, increasing the risk of automated or stealthy attacks. The vulnerability affects devices running NB SDK release 3.6 and earlier versions. The CVSS v3.1 base score is 9.8, indicating a critical severity level, with an attack vector of network (AV:N), no privileges required (PR:N), no user interaction (UI:N), and impacts on confidentiality, integrity, and availability (C:H/I:H/A:H). Although no known exploits have been reported in the wild yet, the high severity and ease of exploitation make this a significant threat. The vulnerability allows an attacker to execute arbitrary code or manipulate system memory, potentially leading to full system compromise or persistent control over the device. Given that these MediaTek chipsets are commonly integrated into Wi-Fi and Bluetooth modules in laptops, IoT devices, and other consumer electronics, the attack surface is broad. The issue is tracked under MediaTek's internal ID MSV-3292 and patch ID WCNCR00412257, but no public patch links are currently available, emphasizing the need for vigilance and proactive mitigation by affected users and organizations.

For European organizations, this vulnerability poses a substantial risk, especially those relying on devices incorporating MediaTek MT79xx series chipsets for wireless connectivity. The ability to escalate privileges locally without user interaction means that malware or malicious insiders could exploit this flaw to gain elevated access, bypass security controls, and potentially move laterally within corporate networks. This could lead to data breaches, intellectual property theft, disruption of services, or deployment of ransomware. Critical infrastructure sectors, including manufacturing, healthcare, and finance, which often use embedded wireless devices, may face operational disruptions or compromise of sensitive information. Additionally, the widespread use of these chipsets in consumer devices used by employees increases the risk of supply chain or endpoint attacks. The lack of known exploits in the wild currently provides a window for mitigation, but the critical severity score and ease of exploitation suggest that threat actors may develop exploits rapidly. Failure to address this vulnerability could result in significant reputational damage and regulatory penalties under GDPR if personal data is compromised.

Organizations should immediately identify and inventory all devices using the affected MediaTek chipsets (MT7902, MT7921, MT7922, MT7925, MT7927) running NB SDK release 3.6 or earlier. Since no public patches are currently linked, organizations should monitor MediaTek's official security advisories and vendor communications for the release of patches or firmware updates addressing CVE-2025-20672. In the interim, applying network segmentation to isolate vulnerable devices, disabling Bluetooth functionality where not required, and enforcing strict access controls can reduce exposure. Endpoint detection and response (EDR) solutions should be tuned to detect anomalous local privilege escalation attempts. Organizations should also implement strict application whitelisting and limit user privileges to minimize the impact of potential exploitation. Regularly updating device firmware and drivers as soon as patches become available is critical. For devices that cannot be patched promptly, consider temporary removal from sensitive networks or replacement with unaffected hardware. Employee awareness training about the risks of Bluetooth-based attacks can further reduce risk vectors.