CVE-2020-27044
📋 TL;DR
This vulnerability allows local privilege escalation on Android 11 devices through memory corruption in the Parcel component. Attackers can exploit a use-after-free condition to gain elevated privileges 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 allowing attackers to execute arbitrary code with system privileges, access sensitive data, or install persistent malware.
Likely Case
Local privilege escalation allowing malicious apps to break out of sandbox and access system resources or other apps' data.
If Mitigated
Limited impact if devices are patched or have strict app installation policies preventing malicious apps from being installed.
🎯 Exploit Status
Exploitation requires local access or malicious app installation. No public exploit code is known, but the vulnerability is well-documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level 2020-12-01 or later
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2020-12-01
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System > Advanced > System update. 2. Install the December 2020 security patch or later. 3. Reboot the device after installation.
🔧 Temporary Workarounds
Restrict app installations
androidOnly allow app installations from trusted sources like Google Play Store with Play Protect enabled.
Disable unknown sources
androidPrevent installation of apps from unknown sources to reduce attack surface.
🧯 If You Can't Patch
- Isolate affected devices from sensitive networks and data
- Implement strict app installation policies and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version. If it shows Android 11 and security patch level is before December 2020, the device is vulnerable.Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level is 2020-12-01 or later in Settings > About phone > Android security patch level.📡 Detection & Monitoring
Log Indicators:
- Unusual system process crashes
- Suspicious privilege escalation attempts in system logs
- Abnormal Parcel component behavior
Network Indicators:
- Unusual outbound connections from system processes
- Suspicious network activity following local privilege escalation
SIEM Query:
source="android_system_logs" AND (process="system_server" AND message="*Parcel*" AND (message="*crash*" OR message="*corruption*"))