CVE-2021-0640
📋 TL;DR
CVE-2021-0640 is an out-of-bounds write vulnerability in Android's StatsdStats.cpp that allows local privilege escalation without user interaction. It affects Android devices running versions 9, 10, and 11, potentially enabling attackers to gain elevated system privileges.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker could exploit this to gain root access on the device, compromising all data and system integrity, leading to complete device control.
Likely Case
Local escalation of privilege to system-level access, allowing unauthorized app installations, data theft, or persistence mechanisms.
If Mitigated
With proper patching, the risk is eliminated; without patching, isolation and monitoring can reduce impact but not prevent exploitation.
🎯 Exploit Status
Exploitation requires local access and knowledge of the vulnerability, but no user interaction, making it feasible for attackers with app installation privileges.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Bulletin August 2021 patches
Vendor Advisory: https://source.android.com/security/bulletin/2021-08-01
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Apply the August 2021 Android security patch. 3. Restart the device to complete the update.
🔧 Temporary Workarounds
Restrict app installations
androidLimit app installations to trusted sources only to reduce the risk of malicious apps exploiting the vulnerability.
Enable 'Install unknown apps' restrictions in Android settings for all apps.
🧯 If You Can't Patch
- Isolate affected devices from sensitive networks and data to limit potential damage.
- Implement strict app vetting and monitoring for unusual activity on vulnerable devices.
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version; if it's 9, 10, or 11 and not patched with August 2021 security update, it is vulnerable.Check Version:
adb shell getprop ro.build.version.releaseVerify Fix Applied:
Verify the Android security patch level is August 2021 or later in Settings > About phone > Android security patch level.📡 Detection & Monitoring
Log Indicators:
- Look for unusual system-level process executions or privilege escalation attempts in Android logs.
Network Indicators:
- No specific network indicators, as exploitation is local.
SIEM Query:
Example: search for events indicating unexpected root access or system file modifications on Android devices.