CVE-2019-9386
📋 TL;DR
This vulnerability allows local privilege escalation on Android 10 devices through NFC server. An attacker could gain system-level privileges by exploiting an out-of-bounds write in the NFC stack. User interaction is required for exploitation, affecting all Android 10 devices with NFC capabilities.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attacker to execute arbitrary code with system server privileges, potentially installing persistent malware or accessing sensitive system data.
Likely Case
Local privilege escalation allowing malware to gain higher privileges than initially granted, potentially bypassing app sandboxing and accessing other apps' data.
If Mitigated
Limited impact if NFC is disabled or device is not running Android 10, though user interaction requirement reduces attack surface.
🎯 Exploit Status
Requires user interaction and local access. No public exploit code available, but vulnerability is well-documented in Android security bulletins.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android 10 security updates from October 2019 onward
Vendor Advisory: https://source.android.com/security/bulletin/android-10
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > Advanced > System update. 2. Install available security updates. 3. Restart device after installation.
🔧 Temporary Workarounds
Disable NFC
androidTurn off NFC functionality to prevent exploitation
Settings > Connected devices > Connection preferences > NFC > Toggle OFF
🧯 If You Can't Patch
- Disable NFC functionality completely on affected devices
- Restrict physical access to devices and educate users about not tapping unknown NFC tags
🔍 How to Verify
Check if Vulnerable:
Check Android version in Settings > About phone > Android version. If version is 10 and security patch level is before October 2019, device is vulnerable.Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android version is 10 with security patch level October 2019 or later in Settings > About phone > Android security patch level.📡 Detection & Monitoring
Log Indicators:
- Unusual NFC service crashes in logcat
- Privilege escalation attempts in system logs
- Unexpected NFC tag interactions
Network Indicators:
- N/A - Local vulnerability only
SIEM Query:
N/A - Device-level vulnerability requiring local monitoring