CVE-2025-20747 is a stack-based buffer overflow vulnerability (CWE-121) identified in the GNSS (Global Navigation Satellite System) service component of multiple MediaTek chipsets, including MT2718, MT2737, MT6835, MT6878, MT6886, MT6897, MT6899, MT6982, MT6985, MT6986, MT6986D, MT6989, MT6990, MT6991, MT8676, MT8678, MT8755, and MT8893. The vulnerability stems from an incorrect bounds check in the GNSS service code, which allows an out-of-bounds write on the stack. This flaw can be exploited by a local attacker who already possesses System-level privileges to escalate their privileges further, potentially gaining higher control over the affected device. The vulnerability does not require any user interaction, which increases the risk of automated or stealthy exploitation. The affected software platforms include Android versions 14.0 and 15.0, openWRT versions 21.02 and 23.05, Yocto 4.0, RDK-B 24Q1, and Zephyr 3.7.0, all running on the aforementioned MediaTek chipsets. These chipsets are commonly embedded in mobile devices, IoT devices, and other embedded systems. Although no public exploits have been reported, the vulnerability's nature and the broad range of affected platforms make it a critical concern. The patch identified as ALPS10010443 addresses this issue, but no direct patch links were provided. The vulnerability's exploitation could compromise device integrity and confidentiality by allowing privilege escalation, potentially leading to unauthorized access to sensitive system components or data.

For European organizations, the impact of CVE-2025-20747 could be significant, particularly for those relying on embedded systems, IoT devices, telecommunications equipment, and industrial control systems that incorporate MediaTek chipsets. Privilege escalation vulnerabilities can allow attackers to bypass security controls, manipulate device behavior, or install persistent malware, which could disrupt operations or lead to data breaches. In sectors such as telecommunications, critical infrastructure, and manufacturing, compromised devices could affect service availability and safety. The lack of user interaction requirement means that once an attacker gains system-level access, they can exploit this vulnerability without alerting users, increasing the risk of stealthy attacks. Additionally, the affected platforms include widely used operating systems in embedded environments, increasing the scope of potential impact. European organizations with supply chains or devices sourced from vendors using these chipsets should be vigilant. The vulnerability could also affect consumer devices, indirectly impacting enterprises through compromised endpoints or networked devices.

To mitigate CVE-2025-20747, European organizations should: 1) Prioritize applying the official patch ALPS10010443 from MediaTek or device vendors as soon as it becomes available to eliminate the vulnerability. 2) Restrict and monitor access to system-level privileges on devices using affected chipsets to reduce the risk of local attackers gaining the necessary privileges to exploit the flaw. 3) Implement strict access controls and segmentation for embedded and IoT devices within enterprise networks to limit lateral movement if a device is compromised. 4) Employ runtime protection and anomaly detection tools focused on GNSS service behavior to identify potential exploitation attempts. 5) Maintain an updated inventory of devices and firmware versions to ensure all affected systems are identified and remediated. 6) Collaborate with device manufacturers and suppliers to confirm patch deployment and receive timely security updates. 7) Conduct regular security assessments and penetration testing on embedded systems to detect privilege escalation vulnerabilities. These steps go beyond generic advice by emphasizing patch management, privilege restriction, network segmentation, and proactive monitoring tailored to the affected platforms and threat characteristics.