CVE-2023-21189
📋 TL;DR
This vulnerability allows an attacker to bypass Android's lock task mode (kiosk mode) due to a logic error in the LockTaskController. An attacker could escalate privileges locally without needing additional execution privileges, potentially gaining unauthorized access to restricted device functions. Only Android 13 devices are affected.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker could escape lock task mode restrictions, access sensitive apps/data, install malware, or take full control of the device.
Likely Case
Unauthorized access to apps and functions that should be restricted in kiosk mode, potentially compromising data or device functionality.
If Mitigated
Limited impact if proper application sandboxing and device management policies are enforced.
🎯 Exploit Status
Requires user interaction and local access. Exploitation involves triggering the logic error in lock task mode.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch June 2023 or later
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2023-06-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > System update. 2. Install the June 2023 security patch or later. 3. Reboot the device after installation.
🔧 Temporary Workarounds
Disable Lock Task Mode
androidTemporarily disable lock task/kiosk mode on affected devices until patched.
adb shell dpm set-device-owner com.example/.DeviceAdminReceiver (to modify device policy)
🧯 If You Can't Patch
- Restrict physical access to devices using lock task mode
- Implement additional application whitelisting and monitoring for kiosk devices
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version. If it's Android 13 without June 2023 security patch, device is vulnerable.Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android version is 13 with security patch level June 5, 2023 or later in Settings > About phone > Android security update.📡 Detection & Monitoring
Log Indicators:
- Unexpected lock task mode exits
- DevicePolicyManager logs showing unauthorized lock task changes
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="android_logs" AND ("LockTaskController" OR "startLockTaskMode") AND ("bypass" OR "unauthorized")