CVE-2025-20796 is a vulnerability in the MediaTek imgsys driver component found in MT6989, MT8796, and MT8893 chipsets, primarily used in Android 15.0 devices. The flaw is an out-of-bounds write caused by insufficient input validation when handling specified indexes, positions, or offsets, classified under CWE-1285. This vulnerability can be exploited locally by an attacker who already has System-level privileges, requiring user interaction to trigger the flaw. Successful exploitation could lead to escalation of privileges, allowing the attacker to gain higher control over the system, potentially compromising confidentiality, integrity, and availability of the device. The vulnerability has a CVSS v3.1 score of 7.8, reflecting high severity with local attack vector, low attack complexity, and requiring privileges but no user interaction. MediaTek has published a patch identified as ALPS10314745 to address this issue. No public exploits have been reported yet, but the vulnerability poses a significant risk to devices using these chipsets if left unpatched.

The vulnerability could allow attackers with existing System privileges to escalate their access 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 functionality. Since the flaw resides in a core media system driver, exploitation could affect a wide range of applications relying on media processing, increasing the risk of widespread compromise. The requirement for local access and user interaction limits remote exploitation but does not eliminate risk in scenarios where attackers have physical or local access, such as through malicious apps or insider threats. The impact is particularly critical for organizations deploying devices with these MediaTek chipsets in sensitive environments, as it could facilitate persistent and stealthy attacks.

Organizations should prioritize deploying the patch ALPS10314745 provided by MediaTek as soon as it becomes available for their devices. Until patched, restrict local access to devices running affected chipsets by enforcing strict device usage policies and limiting installation of untrusted applications that could trigger the vulnerability. Employ mobile device management (MDM) solutions to monitor and control device configurations and app permissions. Conduct regular security audits and user training to reduce the risk of social engineering that could lead to the required user interaction for exploitation. Additionally, implement runtime protections such as application sandboxing and privilege separation to minimize the impact of potential privilege escalations. Monitoring for unusual local activity on devices with these chipsets can also help detect exploitation attempts early.