CVE-2021-0565
📋 TL;DR
This vulnerability allows local privilege escalation on Android 11 devices through a race condition in the audio subsystem. Attackers can exploit a use-after-free bug in AudioStream.cpp to gain elevated privileges without user interaction. Only Android 11 devices with unpatched June 2021 security updates 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 malicious apps to break out of sandbox and access other apps' data or system resources.
If Mitigated
No impact if patched with June 2021 Android security update; otherwise limited to local attackers with physical or app-based access.
🎯 Exploit Status
Race condition exploitation requires precise timing; no public exploits known but technically sophisticated attackers could develop them.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level June 2021 or later
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2021-06-01
Restart Required: Yes
Instructions:
1. Check for Android updates in Settings > System > Advanced > System update. 2. Install June 2021 or later security update. 3. Reboot device after installation.
🔧 Temporary Workarounds
No effective workarounds
allThis is a kernel-level vulnerability requiring patching; no configuration changes can mitigate it.
🧯 If You Can't Patch
- Replace affected devices with updated Android versions
- Isolate vulnerable devices from sensitive networks and data
🔍 How to Verify
Check if Vulnerable:
Check Settings > About phone > Android version (must be 11) and Security patch level (must be before June 2021).Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Security patch level shows June 2021 or later in Settings > About phone.📡 Detection & Monitoring
Log Indicators:
- Kernel crash logs mentioning AudioStream.cpp or wrapUserThread
- Unexpected privilege escalation attempts in audit logs
Network Indicators:
- None - purely local exploitation
SIEM Query:
Search for: 'AudioStream.cpp' OR 'wrapUserThread' OR 'A-174801970' in system logs