CVE-2025-20797 is a stack overflow vulnerability classified under CWE-121, discovered in the battery management component of numerous MediaTek System on Chips (SoCs), including MT2718, MT6765, MT6768, MT6781, MT6833, MT6835, MT6853, MT6855, MT6877, MT6879, MT6893, MT6985, MT6989, MT6991, MT8186, MT8188, MT8196, MT8367, MT8391, MT8676, MT8678, MT8696, MT8766, MT8768, MT8781, MT8786, MT8788E, MT8791T, MT8792, MT8793, MT8796, MT8873, MT8883, and MT8893. These chipsets are integrated into many Android devices running versions 14.0, 15.0, and 16.0. The vulnerability stems from a missing bounds check in the battery subsystem, which allows an out-of-bounds write on the stack. This flaw can be exploited locally by an attacker who already possesses System-level privileges, enabling them to escalate privileges further, potentially gaining higher control over the device. The attack does not require user interaction, increasing its risk in environments where local access is possible. The CVSS v3.1 score is 7.8 (high), reflecting the significant impact on confidentiality, integrity, and availability, combined with relatively low attack complexity and no user interaction needed. Although no known exploits are currently reported in the wild, the vulnerability represents a critical risk for devices using these MediaTek chipsets. The issue was reserved in November 2024 and published in January 2026, with patches referenced by MediaTek under internal IDs (ALPS10315812, MSV-5534). The vulnerability's exploitation could allow attackers to execute arbitrary code or disrupt device operations, severely impacting device security.

For European organizations, the impact of CVE-2025-20797 is significant, especially for enterprises and critical infrastructure relying on Android devices powered by affected MediaTek chipsets. Successful exploitation could lead to local privilege escalation, enabling attackers to bypass security controls, access sensitive data, or disrupt device functionality. This could compromise confidentiality of corporate communications, integrity of device operations, and availability of mobile services. Organizations with bring-your-own-device (BYOD) policies or mobile workforce using vulnerable devices face increased risk of lateral movement or targeted attacks. The vulnerability's local nature means attackers need initial system-level access, which could be obtained via other vulnerabilities or insider threats, making it a potent escalation vector. The broad range of affected chipsets means many consumer and enterprise devices are at risk, potentially impacting sectors such as finance, healthcare, and government services across Europe. The absence of known exploits currently provides a window for proactive mitigation before widespread exploitation occurs.

To mitigate CVE-2025-20797, European organizations should prioritize the following actions: 1) Identify and inventory all Android devices using affected MediaTek chipsets and running Android versions 14.0, 15.0, or 16.0. 2) Apply official patches from device manufacturers or MediaTek as soon as they become available, ensuring firmware and OS updates include the fix for this vulnerability. 3) Restrict local system-level access to trusted personnel and enforce strict access controls to minimize the risk of initial compromise. 4) Employ mobile device management (MDM) solutions to enforce security policies, monitor device integrity, and detect anomalous behavior indicative of privilege escalation attempts. 5) Educate users and administrators about the risks of local privilege escalation and the importance of timely updates. 6) Implement layered security controls such as application sandboxing and runtime protections to limit the impact of potential exploits. 7) Monitor security advisories from MediaTek and Android OEMs for updates or emerging exploit reports. 8) Consider network segmentation and endpoint detection and response (EDR) tools to detect and contain lateral movement stemming from compromised devices. These measures go beyond generic patching by emphasizing device inventory, access control, and active monitoring tailored to the vulnerability's characteristics.