CVE-2021-0675
📋 TL;DR
CVE-2021-0675 is an out-of-bounds write vulnerability in the ALAC (Apple Lossless Audio Codec) decoder used in MediaTek chipsets. This allows local attackers to escalate privileges without user interaction or additional permissions. The vulnerability affects devices using MediaTek chipsets with the vulnerable ALAC decoder implementation.
💻 Affected Systems
- MediaTek chipset-based devices
- Smartphones
- Tablets
- IoT 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 with root-level access, allowing installation of persistent malware, data theft, and full device control.
Likely Case
Local privilege escalation from a limited user account to root/system privileges on affected devices.
If Mitigated
No impact if patched; limited impact if proper application sandboxing and privilege separation are enforced.
🎯 Exploit Status
Exploitation requires local access but no user interaction. The vulnerability is in a widely used audio codec, making it potentially attractive to attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patch ID: ALPS06064258
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/December-2021
Restart Required: Yes
Instructions:
1. Check device manufacturer for security updates. 2. Apply MediaTek security patch ALPS06064258. 3. Update device firmware to latest version. 4. Reboot device after update.
🔧 Temporary Workarounds
Disable ALAC audio processing
allDisable or restrict ALAC audio file processing if not required
Application sandboxing
allEnforce strict application sandboxing to limit privilege escalation impact
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges
- Monitor for suspicious privilege escalation attempts and unusual process behavior
🔍 How to Verify
Check if Vulnerable:
Check device firmware version and security patch level. Look for MediaTek security patch ALPS06064258 in system updates.Check Version:
On Android: 'getprop ro.build.fingerprint' or check Settings > About Phone > Build NumberVerify Fix Applied:
Verify that security patch ALPS06064258 is applied in device settings or by checking build fingerprint.📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege escalation events
- ALAC decoder process crashes
- Suspicious audio file processing
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Process creation where parent process is audio-related and child process has elevated privileges