CVE-2021-0466
📋 TL;DR
This vulnerability in Android's ClientModeImpl.java allows a proximal attacker to track a device via a unique identifier, leading to remote information disclosure without requiring user interaction or additional privileges. It affects Android 10 devices, potentially exposing sensitive location or usage data to nearby malicious actors.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker could persistently track a device's movements and usage patterns, leading to privacy violations, targeted attacks, or data leakage.
Likely Case
Proximal attackers in public spaces could gather device identifiers for tracking or profiling purposes, compromising user privacy.
If Mitigated
With proper patching, the vulnerability is eliminated, preventing unauthorized tracking and information disclosure.
🎯 Exploit Status
Exploitation does not require authentication or user interaction, making it straightforward for attackers with proximity access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level 2021-05-01 or later
Vendor Advisory: https://source.android.com/security/bulletin/2021-05-01
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Apply the Android security update dated May 2021 or later. 3. Restart the device after installation to ensure the patch is active.
🔧 Temporary Workarounds
Disable Wi-Fi when not in use
androidTurn off Wi-Fi to prevent proximal attackers from accessing the vulnerable component via local networks.
Toggle Wi-Fi off in device settings or use quick settings panel
Use a VPN on untrusted networks
androidEncrypt network traffic to reduce the risk of identifier leakage, though this may not fully mitigate the vulnerability.
Install and enable a trusted VPN app from the Google Play Store
🧯 If You Can't Patch
- Limit device use on public or untrusted Wi-Fi networks to reduce exposure to proximal attackers.
- Monitor for unusual network activity or tracking attempts using security apps that detect identifier leaks.
🔍 How to Verify
Check if Vulnerable:
Check the Android security patch level in Settings > About phone > Android version. If the patch level is earlier than May 2021, the device is likely vulnerable.Check Version:
Use 'adb shell getprop ro.build.version.security_patch' on a connected device or check in Settings > About phone.Verify Fix Applied:
Confirm the security patch level is May 2021 or later in device settings; no further tracking via this identifier should occur.📡 Detection & Monitoring
Log Indicators:
- Unusual Wi-Fi connection attempts or identifier broadcasts in system logs, though specific logs may not be readily available.
Network Indicators:
- Suspicious network probes or traffic from unknown devices in proximity, detectable via network monitoring tools.
SIEM Query:
Not typically applicable for mobile devices; focus on endpoint detection for abnormal network behavior or use mobile device management (MDM) logs.