CVE-2025-20764 is a security vulnerability identified in multiple MediaTek chipsets widely used in Android smartphones and tablets. The vulnerability is classified as an out-of-bounds write (CWE-787) occurring within the 'smi' component due to a missing bounds check. This flaw allows a local attacker who has already obtained System-level privileges to perform an out-of-bounds write, potentially leading to escalation of privileges beyond the System level. The vulnerability affects a broad range of MediaTek chipsets including MT6739, MT6761, MT6765, MT6768, MT6781, MT6789, MT6833, MT6835, MT6853, MT6855, MT6877, MT6878, MT6879, MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899, MT6983, MT6985, MT6989, MT6991, MT8196, MT8676, MT8678, MT8792, MT8793, MT8796, MT8873, and MT8893, across Android versions 14.0 to 16.0. Exploitation does not require user interaction, increasing the risk in environments where an attacker has already compromised system-level access. Although no public exploits have been reported, the vulnerability's nature allows attackers to manipulate memory beyond intended boundaries, potentially leading to arbitrary code execution, system instability, or further privilege escalation. The vulnerability was reserved in November 2024 and published in December 2025, with patches indicated but no direct patch links provided. The absence of a CVSS score necessitates an assessment based on impact and exploitability factors.

For European organizations, the impact of CVE-2025-20764 is significant, especially those relying on Android devices powered by affected MediaTek chipsets. The vulnerability enables attackers who have already gained System privileges to escalate their access, potentially compromising device confidentiality, integrity, and availability. This could lead to unauthorized access to sensitive corporate data, manipulation of device functions, or disruption of services dependent on mobile endpoints. Sectors such as finance, healthcare, government, and critical infrastructure that utilize Android devices for secure communications or operations are particularly at risk. The lack of user interaction requirement means that once initial compromise occurs, attackers can exploit this vulnerability silently. This elevates the threat level in environments where endpoint security is weak or where insider threats exist. Additionally, the widespread use of MediaTek chipsets in cost-effective Android devices increases the attack surface across European markets.

To mitigate CVE-2025-20764, organizations should prioritize the following actions: 1) Apply official patches from MediaTek or device manufacturers as soon as they become available to address the out-of-bounds write flaw. 2) Restrict System-level privileges strictly to trusted applications and processes to minimize the risk of privilege escalation. 3) Employ mobile device management (MDM) solutions to enforce security policies and monitor for unusual privilege escalations or suspicious behaviors on Android devices. 4) Conduct regular security audits and vulnerability assessments on mobile endpoints to detect potential compromises early. 5) Educate users and administrators about the risks of granting elevated privileges and the importance of installing updates promptly. 6) Implement endpoint detection and response (EDR) tools capable of monitoring low-level system activities on Android devices, focusing on memory corruption indicators. 7) Where feasible, consider device replacement or segmentation strategies for devices running unpatched vulnerable chipsets. These steps go beyond generic advice by focusing on privilege management, proactive monitoring, and patch management tailored to the specific chipset vulnerability.