CVE-2025-20636
📋 TL;DR
CVE-2025-20636 is an out-of-bounds write vulnerability in secmem that allows local privilege escalation. Attackers with System privilege can exploit this without user interaction to gain elevated access. This affects devices using MediaTek chipsets with vulnerable secmem implementations.
💻 Affected Systems
- MediaTek chipset-based devices
- Android devices with MediaTek processors
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code with kernel privileges, potentially installing persistent malware or accessing sensitive data.
Likely Case
Local privilege escalation from System to kernel-level access, enabling further system manipulation or credential theft.
If Mitigated
Limited impact if proper privilege separation and kernel hardening are implemented, though System privilege access remains concerning.
🎯 Exploit Status
Exploitation requires System privilege first; out-of-bounds write manipulation requires specific memory knowledge.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patch ID: ALPS09403554
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/February-2025
Restart Required: Yes
Instructions:
1. Check device manufacturer for security updates. 2. Apply MediaTek patch ALPS09403554. 3. Reboot device after patch installation. 4. Verify patch application through version checks.
🔧 Temporary Workarounds
Restrict System Privilege Access
androidLimit applications and users with System privilege to reduce attack surface.
# Review and minimize apps with system privileges
# Use Android's permission management tools
🧯 If You Can't Patch
- Implement strict application sandboxing and privilege separation
- Monitor for unusual System privilege usage and privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check device manufacturer security bulletins for MediaTek patch status; examine secmem version if accessible.Check Version:
# Device-specific; typically in Settings > About Phone > Build Number or security patch levelVerify Fix Applied:
Verify patch ALPS09403554 is applied through device security settings or manufacturer update logs.📡 Detection & Monitoring
Log Indicators:
- Unexpected secmem access attempts
- Privilege escalation logs from System to kernel
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
source="kernel" AND "secmem" AND ("out of bounds" OR "privilege escalation")