CVE-2021-0426
📋 TL;DR
This CVE describes a heap buffer overflow vulnerability in Android's LogEvent.cpp that allows local privilege escalation without user interaction. Attackers can exploit this to gain elevated privileges on affected Android devices. Only Android 11 devices are affected.
💻 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 system privileges, potentially installing persistent malware or accessing sensitive data.
Likely Case
Local privilege escalation allowing attackers to bypass application sandboxing and access other apps' data or system resources.
If Mitigated
Limited impact if devices are patched or have security controls like SELinux enforcing mode and app sandboxing properly configured.
🎯 Exploit Status
Exploitation requires local access to the device. No user interaction needed once access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level 2021-04-01 or later
Vendor Advisory: https://source.android.com/security/bulletin/2021-04-01
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System > Advanced > System update. 2. Install the April 2021 security patch or later. 3. Reboot the device after installation.
🔧 Temporary Workarounds
No effective workarounds
allThis is a core framework vulnerability requiring patching. No configuration changes can mitigate it.
🧯 If You Can't Patch
- Isolate affected devices from sensitive networks and data
- Monitor for suspicious privilege escalation attempts and unusual system behavior
🔍 How to Verify
Check if Vulnerable:
Check Android version and security patch level in Settings > About phone > Android version and Security patch levelCheck Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Security patch level shows '2021-04-01' or later date in Settings > About phone📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation in system logs
- SELinux denials related to logd or system_server
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Not applicable for typical SIEM monitoring as this is a local device vulnerability