CVE-2025-20798
📋 TL;DR
This vulnerability allows local privilege escalation on MediaTek devices through an out-of-bounds write in the battery subsystem. Attackers with initial System privilege access can exploit this to gain higher privileges without user interaction. This affects devices using MediaTek chipsets with vulnerable battery firmware.
💻 Affected Systems
- MediaTek chipset-based devices (smartphones, tablets, IoT devices)
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to execute arbitrary code with kernel privileges, install persistent malware, or bypass security controls.
Likely Case
Local privilege escalation from System to higher kernel privileges, enabling further system manipulation or data access.
If Mitigated
Limited impact if proper privilege separation and kernel hardening are implemented, though exploitation still possible with initial System access.
🎯 Exploit Status
Exploitation requires System privilege first; out-of-bounds write manipulation requires specific knowledge of battery subsystem.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to MediaTek patch ID ALPS10315812
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/January-2026
Restart Required: Yes
Instructions:
1. Contact device manufacturer for firmware updates. 2. Apply MediaTek-provided patch ALPS10315812. 3. Reboot device after patch installation. 4. Verify patch application through version checks.
🔧 Temporary Workarounds
Restrict System Privilege Access
androidLimit which applications and users have System privilege to reduce attack surface.
Review and restrict Android system permissions via device management policies
🧯 If You Can't Patch
- Implement strict application sandboxing and privilege separation
- Monitor for unusual battery subsystem activity or privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against MediaTek advisory; examine battery subsystem version if accessible.Check Version:
adb shell getprop ro.build.fingerprint (for Android devices) or check device firmware settingsVerify Fix Applied:
Verify patch ALPS10315812 is applied through firmware version checks or vendor verification tools.📡 Detection & Monitoring
Log Indicators:
- Unusual battery subsystem process activity
- Privilege escalation attempts from System context
- Kernel panic or crashes related to battery driver
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
Process creation from battery subsystem with elevated privileges OR kernel module loading from unusual contexts