CVE-2021-0591
📋 TL;DR
This vulnerability allows a malicious app on an Android device to send privileged broadcast intents, potentially gaining elevated permissions. It affects Android devices running versions 8.1 through 11, requiring user interaction for exploitation.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation leading to unauthorized access to sensitive device functions or data.
Likely Case
Malicious app gaining additional permissions to access restricted features like Bluetooth or location data.
If Mitigated
Limited impact if devices are patched or have strict app permissions, preventing unauthorized intent broadcasts.
🎯 Exploit Status
Exploitation requires a malicious app to be installed and user interaction, making it moderately complex.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Bulletin August 2021 patches
Vendor Advisory: https://source.android.com/security/bulletin/2021-08-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in device settings. 2. Install the August 2021 security patch or later. 3. Restart the device after installation.
🔧 Temporary Workarounds
Disable Bluetooth or restrict app permissions
androidReduce risk by disabling Bluetooth when not in use or limiting app permissions to prevent malicious intent broadcasts.
🧯 If You Can't Patch
- Restrict installation of untrusted apps via device management policies.
- Monitor for unusual app behavior or permission requests using mobile security tools.
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version; if it's 8.1 to 11 and not patched with August 2021 update, it may be vulnerable.Check Version:
adb shell getprop ro.build.version.releaseVerify Fix Applied:
Verify the Android security patch level is August 2021 or later in Settings > About phone > Android security patch level.📡 Detection & Monitoring
Log Indicators:
- Log entries showing unexpected broadcast intents from BluetoothPermissionActivity or permission escalation attempts.
Network Indicators:
- None, as this is a local privilege escalation vulnerability.
SIEM Query:
Example: Search for logs with event IDs related to Bluetooth permission activities or app privilege changes on Android devices.