CVE-2021-0547
📋 TL;DR
This vulnerability allows local attackers to escalate privileges on Android 11 devices by supplying malicious values to the GPS HAL handler without requiring user interaction. It affects Android 11 devices, particularly those with specific HAL implementations, and could lead to undefined behavior or system compromise. Exploitation requires local access to the device.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise, allowing attackers to execute arbitrary code with elevated privileges, potentially leading to data theft, surveillance, or persistent malware installation.
Likely Case
Local privilege escalation enabling unauthorized access to sensitive system functions or GPS data manipulation, disrupting device operations.
If Mitigated
Minimal impact if patched; without patch, risk is reduced by limiting local access and monitoring for suspicious GPS-related activity.
🎯 Exploit Status
Exploitation requires local access and knowledge of the GPS HAL interface; no public exploits are documented, but the vulnerability is straightforward for skilled attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level June 2021 or later
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2021-06-01
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Apply the June 2021 Android security patch or later. 3. Restart the device after installation to ensure the fix is active.
🔧 Temporary Workarounds
Restrict Local App Permissions
androidLimit permissions for untrusted apps to reduce attack surface; this does not fully mitigate but lowers risk.
Use Android settings to review and revoke unnecessary app permissions, especially for GPS access.
🧯 If You Can't Patch
- Isolate affected devices from sensitive networks and monitor for unusual GPS activity or privilege escalation attempts.
- Implement strict access controls to prevent unauthorized local access to devices, such as using device management policies.
🔍 How to Verify
Check if Vulnerable:
Check the Android security patch level in Settings > About phone > Android version; if before June 2021, the device is likely vulnerable.Check Version:
Use 'adb shell getprop ro.build.version.security_patch' to check the security patch date via ADB.Verify Fix Applied:
Confirm the security patch level is June 2021 or later in device settings after applying updates.📡 Detection & Monitoring
Log Indicators:
- Look for unusual GPS-related activity or permission escalation attempts in system logs, such as unexpected calls to NetInitiatedActivity.
Network Indicators:
- None, as this is a local vulnerability with no network exploitation component.
SIEM Query:
Example: Search for log entries containing 'NetInitiatedActivity' or 'GPS HAL' with error or warning flags in Android device logs.