CVE-2021-0432
📋 TL;DR
This CVE describes a use-after-free vulnerability in Android's StatsPullerManager due to a race condition in ClearPullerCacheIfNecessary and ForceClearPullerCache functions. It allows local privilege escalation without requiring user interaction or additional execution privileges. Only Android 11 devices are affected.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker with local access could exploit this race condition to execute arbitrary code with elevated privileges, potentially gaining full control over the device.
Likely Case
Local privilege escalation allowing an attacker to gain higher privileges than their current user context, potentially accessing sensitive data or performing unauthorized actions.
If Mitigated
With proper patching, the vulnerability is eliminated; without patching, risk is limited to attackers with local access to the device.
🎯 Exploit Status
Exploitation requires local access and knowledge of the race condition timing. No public exploit code has been disclosed.
🛠️ 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 Android framework vulnerability that requires patching at the OS level.
🧯 If You Can't Patch
- Restrict physical access to vulnerable devices
- Implement application allowlisting to prevent malicious apps from exploiting the vulnerability
🔍 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 2021-04-01 or later in Settings > About phone.📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation attempts in system logs
- Crash reports from StatsPullerManager
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Not applicable for network detection; monitor device logs for privilege escalation patterns