CVE-2023-21247
📋 TL;DR
This vulnerability allows local attackers to bypass device policy restrictions for Bluetooth scanning without proper permission checks. It enables local privilege escalation on affected Android devices without requiring user interaction. Only Android devices with vulnerable Settings app versions are affected.
💻 Affected Systems
- Android Settings application
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker with physical access or malicious app could gain elevated privileges, potentially accessing restricted device features or sensitive data normally protected by device policies.
Likely Case
Malicious apps could bypass Bluetooth scanning restrictions to perform unauthorized device discovery or connection attempts without user knowledge.
If Mitigated
With proper Android security updates applied, the vulnerability is completely patched with no residual risk.
🎯 Exploit Status
Exploitation requires local access or malicious app installation. No user interaction needed once access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: July 2023 Android Security Patch or later
Vendor Advisory: https://source.android.com/security/bulletin/2023-07-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > System update. 2. Install July 2023 or later security patch. 3. Reboot device after installation.
🔧 Temporary Workarounds
Disable Bluetooth scanning via policy
androidConfigure device policy to disable Bluetooth scanning features entirely
Restrict app installation
androidUse Android Enterprise or MDM solutions to restrict installation of untrusted applications
🧯 If You Can't Patch
- Implement strict mobile device management (MDM) policies to control app installation and device features
- Monitor for unusual Bluetooth scanning activity or policy bypass attempts
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone > Android version > Security patch level. If before July 2023, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level shows July 2023 or later date. Test Bluetooth scanning restrictions via device policy to ensure they are enforced.📡 Detection & Monitoring
Log Indicators:
- Unauthorized Bluetooth scanning attempts
- Device policy restriction bypass logs
- Settings app permission violation events
Network Indicators:
- Unexpected Bluetooth discovery or pairing attempts from restricted devices
SIEM Query:
source="android_logs" AND (event="bluetooth_scan_bypass" OR event="policy_violation" AND component="Settings")🔗 References
- https://android.googlesource.com/platform/packages/apps/Settings/+/edd4023805bc7fa54ae31de222cde02b9012bbc4
- https://source.android.com/security/bulletin/2023-07-01
- https://android.googlesource.com/platform/packages/apps/Settings/+/edd4023805bc7fa54ae31de222cde02b9012bbc4
- https://source.android.com/security/bulletin/2023-07-01
