CVE-2022-20047
📋 TL;DR
CVE-2022-20047 is an out-of-bounds write vulnerability in MediaTek video decoder components that allows local privilege escalation without user interaction. Attackers can exploit this to gain elevated system privileges on affected devices. This primarily affects Android devices using MediaTek chipsets.
💻 Affected Systems
- MediaTek chipset-based Android devices
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root privileges, allowing installation of persistent malware, data theft, and device control.
Likely Case
Local privilege escalation to gain elevated permissions for further attacks or data access.
If Mitigated
Limited impact if proper kernel hardening, SELinux policies, and privilege separation are implemented.
🎯 Exploit Status
Requires local access but no user interaction. Exploitation requires understanding of video decoder memory structures.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware with patch ID ALPS05917489
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/March-2022
Restart Required: Yes
Instructions:
1. Check device manufacturer for security updates. 2. Apply Android security patch from March 2022 or later. 3. Update MediaTek firmware if available. 4. Reboot device after update.
🔧 Temporary Workarounds
Disable vulnerable video codecs
androidRestrict or disable MediaTek video decoder functionality if not required
Enhanced SELinux policies
androidImplement strict SELinux policies to limit video decoder process privileges
🧯 If You Can't Patch
- Implement strict application sandboxing and privilege separation
- Monitor for unusual video decoder process behavior and privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level (Settings > About phone > Android version). If before March 2022, likely vulnerable. Check MediaTek firmware version via engineering mode.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android security patch level is March 2022 or later. Check with manufacturer for specific MediaTek patch confirmation.📡 Detection & Monitoring
Log Indicators:
- Unusual video decoder process crashes
- Privilege escalation attempts in kernel logs
- SELinux denials related to video decoder
Network Indicators:
- None - local exploit only
SIEM Query:
Process creation where parent is video decoder service with elevated privileges