CVE-2021-0310
📋 TL;DR
This CVE describes a use-after-free vulnerability in Android's LazyServiceRegistrar component that could allow local privilege escalation. An attacker could exploit this memory corruption to gain elevated privileges on affected Android devices without user interaction. Only Android 11 devices are affected.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise with root/system-level access, allowing complete control over the device, data theft, and persistence.
Likely Case
Local privilege escalation to gain elevated permissions for malicious activities like installing malware, accessing protected data, or bypassing security controls.
If Mitigated
Limited impact if devices are patched or have additional security controls like SELinux enforcing mode and app sandboxing.
🎯 Exploit Status
Exploitation requires local access to the device. No user interaction needed once access is obtained. Memory corruption vulnerabilities typically require specific conditions to be reliably exploitable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level 2021-01-01 or later
Vendor Advisory: https://source.android.com/security/bulletin/2021-01-01
Restart Required: Yes
Instructions:
1. Check current Android security patch level in Settings > About phone > Android version. 2. Apply the January 2021 Android security update via Settings > System > System update. 3. Reboot device after update completes.
🔧 Temporary Workarounds
Disable unnecessary services
androidReduce attack surface by disabling unused system services that might use the vulnerable component
Enhanced SELinux policies
androidImplement stricter SELinux policies to limit privilege escalation paths
🧯 If You Can't Patch
- Isolate affected devices from sensitive networks and data
- Implement application allowlisting to prevent unauthorized app execution
🔍 How to Verify
Check if Vulnerable:
Check Android version and security patch level: Settings > About phone > Android version. If Android 11 with patch level earlier than 2021-01-01, device is vulnerable.Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android security patch level is 2021-01-01 or later in Settings > About phone > Android version.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- System service crashes
- Unexpected privilege escalation attempts in audit logs
Network Indicators:
- Unusual outbound connections from system processes
- Unexpected network activity from elevated processes
SIEM Query:
source="android_logs" AND (event_type="kernel_panic" OR process_name="LazyServiceRegistrar" AND event="crash")