CVE-2025-20798: Android Privilege Escalation Vulnerability

CVE-2025-20798 Overview

CVE-2025-20798 is an out-of-bounds write vulnerability affecting the battery driver component in MediaTek chipsets running on Google Android devices. The vulnerability exists due to a missing bounds check in the battery subsystem, which allows an attacker who has already obtained System privilege to escalate privileges further through local access. This vulnerability does not require user interaction for successful exploitation.

Critical Impact

Local privilege escalation on Android devices with MediaTek chipsets, enabling attackers with System privilege to gain elevated access without user interaction.

Affected Products

• Google Android 14.0, 15.0, and 16.0
• MediaTek MT6765, MT6768, MT6781, MT6833, MT6835, MT6853, MT6855, MT6877, MT6879, MT6893, MT6985, MT6989, MT6991 (Mobile SoCs)
• MediaTek MT8186, MT8188, MT8196, MT8367, MT8391, MT8676, MT8678, MT8696, MT8766, MT8768, MT8781, MT8786, MT8788e, MT8791t, MT8792, MT8793, MT8796, MT8873, MT8883, MT8893, MT2718 (Tablet/IoT SoCs)

Discovery Timeline

• January 6, 2026 - CVE-2025-20798 published to NVD
• January 8, 2026 - Last updated in NVD database

Technical Details for CVE-2025-20798

Vulnerability Analysis

This out-of-bounds write vulnerability (CWE-787) resides in the battery driver component used across numerous MediaTek chipsets. The flaw occurs when the driver fails to properly validate buffer boundaries before performing write operations, creating a memory corruption condition that can be leveraged for privilege escalation.

The vulnerability is particularly concerning because it affects a wide range of MediaTek chipsets used in smartphones, tablets, and IoT devices running Android 14.0 through 16.0. The battery driver operates at a privileged level within the Android system, making it an attractive target for attackers seeking to elevate their access on compromised devices.

While exploitation requires the attacker to already possess System privilege, successful exploitation could allow further escalation, potentially gaining kernel-level access or persisting malicious code at a deeper system level. The absence of a required user interaction makes this vulnerability suitable for automated exploitation chains.

Root Cause

The root cause of CVE-2025-20798 is a missing bounds check in the battery driver code. When processing certain battery-related data or commands, the driver writes to a memory buffer without first verifying that the destination address and data size fall within the allocated buffer boundaries. This oversight allows specially crafted input to trigger writes beyond the intended memory region, corrupting adjacent memory structures.

Attack Vector

The attack vector is local, requiring the attacker to have already compromised the device and obtained System-level privileges. From this position, an attacker can interact with the vulnerable battery driver through system calls or device-specific interfaces. By providing malformed input designed to bypass the missing bounds validation, the attacker triggers an out-of-bounds write condition.

The out-of-bounds write can be used to overwrite critical kernel data structures, function pointers, or security tokens, ultimately achieving higher privilege levels such as kernel execution or bypassing additional security controls. Since no user interaction is required, this exploitation can occur silently in the background once System privilege has been obtained through a separate attack chain.

Detection Methods for CVE-2025-20798

Indicators of Compromise

• Unusual battery driver service crashes or restarts in system logs
• Unexpected memory allocation patterns related to battery subsystem components
• Evidence of privilege escalation attempts from System to kernel level
• Anomalous system call activity targeting MediaTek-specific device drivers
• Modified or tampered battery driver binaries on affected devices

Detection Strategies

• Monitor Android system logs (logcat) for battery driver exceptions, crashes, or memory corruption errors
• Implement kernel integrity monitoring to detect unauthorized modifications to driver code or data structures
• Deploy endpoint detection solutions capable of identifying out-of-bounds memory access patterns
• Use SentinelOne Mobile to detect privilege escalation attempts and anomalous system behavior on Android devices

Monitoring Recommendations

• Enable verbose logging for MediaTek driver components during security investigations
• Configure alerting for repeated battery driver service failures or abnormal restart patterns
• Implement file integrity monitoring on critical system driver binaries
• Review system audit logs for suspicious interactions with device-specific driver interfaces

How to Mitigate CVE-2025-20798

Immediate Actions Required

• Apply the security patch identified as ALPS10315812 from MediaTek immediately
• Update affected Android devices to the latest available firmware from device manufacturers
• Restrict local access to affected devices and limit System-level privileges to trusted applications only
• Enable SentinelOne Mobile protection to detect and prevent exploitation attempts

Patch Information

MediaTek has released a security patch addressing this vulnerability, identified by Patch ID ALPS10315812 and Issue ID MSV-5533. The fix has been included in the MediaTek Security Bulletin January 2026. Device manufacturers incorporating affected MediaTek chipsets should integrate this patch into their firmware updates. End users should apply firmware updates from their device manufacturers as soon as they become available.

Workarounds

• Limit installation of applications to trusted sources to reduce the risk of initial System compromise
• Disable unnecessary device features and services that could provide attack paths to System privilege
• Implement application sandboxing and restrict inter-process communication where possible
• Consider using device management solutions to enforce security policies on affected devices
• Monitor device behavior for signs of compromise while awaiting official patches

# Check Android security patch level on affected devices
adb shell getprop ro.build.version.security_patch

# Verify MediaTek chipset model
adb shell getprop ro.hardware

# Review battery driver logs for anomalies
adb logcat | grep -i "battery\|mtk\|alps"