CVE-2025-20767 is a vulnerability classified under CWE-787 (Out-of-bounds Write) affecting a wide range of MediaTek System-on-Chip (SoC) models including MT2718, 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, and MT8793. These chipsets are integrated into devices running Android versions 14.0, 15.0, and 16.0. The vulnerability stems from an integer overflow in the display subsystem, which leads to an out-of-bounds write condition. This memory corruption flaw can be exploited locally by an attacker who already has System-level privileges on the device, enabling escalation to higher privileges or potentially full control over the device. The attack does not require user interaction, increasing the risk of stealthy exploitation. The CVSS v3.1 base score is 7.8, indicating high severity, with metrics showing low attack complexity, low privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No public exploits are known yet, but the vulnerability is significant due to the large number of affected devices and the critical nature of the flaw. The issue is tracked under MediaTek’s internal ID MSV-4807 and patch ID ALPS10196993, though no public patch links are currently available. This vulnerability highlights the risks in complex SoC firmware and the importance of rigorous integer overflow checks in low-level hardware drivers.

The vulnerability allows a local attacker with System privileges to escalate their privileges further, potentially gaining full control over the affected device. This can lead to unauthorized access to sensitive data, modification or deletion of critical system files, and disruption of device availability. The broad range of affected MediaTek chipsets means millions of Android devices globally could be impacted, especially those running Android 14 through 16. The lack of required user interaction facilitates stealthy exploitation, increasing the risk of persistent compromise. Organizations relying on affected devices for critical communications, mobile workforce, or IoT deployments face risks of data breaches, espionage, and operational disruption. The vulnerability undermines the security boundary of the operating system, threatening confidentiality, integrity, and availability simultaneously. Although no exploits are known in the wild yet, the high severity and ease of exploitation warrant urgent mitigation to prevent future attacks.

Organizations and users should monitor MediaTek and device vendor advisories closely and apply security patches as soon as they become available. Until patches are deployed, restrict local access to devices, especially limiting System-level access to trusted users and processes only. Employ runtime protections such as memory protection mechanisms and integrity monitoring to detect anomalous behavior indicative of exploitation attempts. Implement strict privilege separation and minimize the number of applications or services running with elevated privileges. Use mobile device management (MDM) solutions to enforce security policies and monitor for suspicious activities. For developers, conduct thorough code audits focusing on integer overflow and memory safety in low-level drivers and firmware. Additionally, consider deploying endpoint detection and response (EDR) tools capable of identifying exploitation patterns related to out-of-bounds memory writes. Finally, educate users and administrators about the risks of privilege escalation vulnerabilities and the importance of timely patching.