CVE-2025-20769 is a stack overflow vulnerability classified under CWE-121, discovered in MediaTek's display subsystem affecting a broad range of MT series chipsets 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 a missing bounds check in the display code, 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 to escalate their privileges further, potentially compromising system integrity or bypassing security controls. Exploitation does not require user interaction, increasing the risk in environments where attackers have gained initial high-level access. However, the vulnerability does not directly allow remote code execution or initial system compromise. The CVSS v3.1 score of 3.4 reflects the low severity due to the requirement of high privileges and limited confidentiality and integrity impact. No public exploits or active exploitation have been reported to date. The vendor has assigned a patch ID ALPS10196993 and issue ID MSV-4804, indicating that a fix is planned or available. The vulnerability highlights the importance of rigorous bounds checking in low-level hardware interface code, especially in widely deployed mobile chipsets.

The primary impact of CVE-2025-20769 is local privilege escalation on devices using affected MediaTek chipsets running Android 14 to 16. An attacker with System privileges could exploit this vulnerability to gain higher privileges or bypass certain security mechanisms, potentially leading to unauthorized access to sensitive system components or data. Although the vulnerability does not allow initial system compromise or remote exploitation, it can be leveraged as part of a multi-stage attack chain to deepen system control. This could affect device integrity and confidentiality, especially in environments where attackers have already obtained elevated access. The vulnerability could impact smartphones, tablets, IoT devices, and embedded systems using these chipsets, potentially disrupting services or enabling persistent malware. Given the widespread use of MediaTek chipsets in consumer electronics globally, the vulnerability poses a risk to millions of devices. However, the low CVSS score and lack of known exploits suggest a limited immediate threat. Organizations relying on affected devices should consider the risk in their threat models, particularly for high-security environments.

To mitigate CVE-2025-20769, organizations and device manufacturers should prioritize applying the official patches released by MediaTek (Patch ID ALPS10196993) as soon as they become available. Until patches are deployed, enforcing strict privilege separation and minimizing the number of processes or users with System-level privileges can reduce exploitation risk. Employing runtime protections such as stack canaries, address space layout randomization (ASLR), and control-flow integrity (CFI) can help detect or prevent exploitation attempts. Security teams should monitor for unusual local privilege escalation attempts and audit logs for suspicious activity related to display subsystem processes. For device manufacturers, conducting thorough code reviews and fuzz testing on hardware interface components can prevent similar vulnerabilities. Additionally, educating users and administrators about the importance of timely updates and restricting physical or local access to devices can further reduce risk. Network segmentation and endpoint detection solutions can help contain potential compromise stemming from this vulnerability.