CVE-2021-0316
📋 TL;DR
This vulnerability allows remote code execution via Bluetooth without user interaction. An attacker can exploit a missing bounds check in Android's Bluetooth AVRCP implementation to write out of bounds and execute arbitrary code. Affects Android devices running versions 8.0 through 11.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise with attacker gaining complete control over the Android device, accessing all data, installing malware, and using the device as a pivot point.
Likely Case
Remote code execution leading to data theft, surveillance, or ransomware deployment on vulnerable devices within Bluetooth range.
If Mitigated
No impact if patched or Bluetooth disabled; limited impact if Bluetooth usage is restricted to trusted devices only.
🎯 Exploit Status
Exploitation requires Bluetooth proximity but no authentication or user interaction.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Bulletin January 2021 patches
Vendor Advisory: https://source.android.com/security/bulletin/2021-01-01
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System > Advanced > System update. 2. Install the January 2021 Android security patch. 3. Reboot the device after installation.
🔧 Temporary Workarounds
Disable Bluetooth
androidTurn off Bluetooth to prevent exploitation via this vector
adb shell settings put global bluetooth_on 0
Settings > Connected devices > Connection preferences > Bluetooth > Toggle off
Restrict Bluetooth visibility
androidSet Bluetooth to non-discoverable mode to reduce attack surface
Settings > Connected devices > Connection preferences > Bluetooth > Device name > Turn off 'Make device visible'
🧯 If You Can't Patch
- Disable Bluetooth completely when not in use
- Restrict Bluetooth usage to trusted, paired devices only in controlled environments
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version. If version is 8.0, 8.1, 9, 10, or 11 without January 2021 patches, device is vulnerable.Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android security patch level is January 2021 or later in Settings > About phone > Android security patch level.📡 Detection & Monitoring
Log Indicators:
- Unusual Bluetooth connection attempts in Bluetooth logs
- AVRCP protocol anomalies
- Crash logs from avrc_pars_tg process
Network Indicators:
- Suspicious Bluetooth traffic patterns
- AVRCP command flooding
SIEM Query:
source="android_logs" AND (process="bluetooth" OR process="avrc") AND (event="buffer_overflow" OR event="out_of_bounds")