CVE-2021-0955
📋 TL;DR
This CVE describes a race condition vulnerability in Android's FuseDaemon that could allow local privilege escalation. An attacker could exploit memory corruption 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 with attacker gaining root/system privileges, allowing installation of persistent malware, data theft, and complete control of the device.
Likely Case
Local attacker gains elevated privileges to access sensitive data, install malicious apps, or modify system settings.
If Mitigated
With proper patching, the vulnerability is eliminated. On unpatched devices, standard Android sandboxing provides some protection but not complete mitigation.
🎯 Exploit Status
Exploitation requires local access and knowledge of race condition timing. No public exploit code has been documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level December 2021 or later
Vendor Advisory: https://source.android.com/security/bulletin/2021-12-01
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System > System update. 2. Install the December 2021 Android security patch or later. 3. Reboot the device after installation.
🔧 Temporary Workarounds
No effective workarounds
allThis is a kernel-level race condition that cannot be mitigated without patching.
🧯 If You Can't Patch
- Restrict physical access to devices
- Implement strict app installation policies and only install apps from trusted sources
🔍 How to Verify
Check if Vulnerable:
Check Android version and security patch level in Settings > About phone > Android version and Security patch level.Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Security patch level shows 'December 1, 2021' or later in Settings > About phone.📡 Detection & Monitoring
Log Indicators:
- Kernel crash logs, unexpected privilege escalation attempts in system logs
Network Indicators:
- None - this is a local exploit
SIEM Query:
Search for kernel panic events or unexpected process privilege changes on Android devices