CVE-2019-9309
📋 TL;DR
This vulnerability in Android's NFC stack allows local privilege escalation through an out-of-bounds write. Attackers can exploit this by tricking users into interacting with malicious NFC content, potentially gaining elevated system privileges. Only Android 10 devices with NFC hardware are affected.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise with attacker gaining root/system-level access, allowing installation of persistent malware, data theft, and device control.
Likely Case
Limited privilege escalation allowing access to sensitive data and system functions normally restricted to the user's current privilege level.
If Mitigated
No impact if patched or if NFC is disabled; minimal impact if proper app sandboxing and SELinux policies are enforced.
🎯 Exploit Status
Requires user interaction with malicious NFC tag; exploit requires bypassing ASLR and other Android security mitigations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android 10 security patch level 2019-10-01 or later
Vendor Advisory: https://source.android.com/security/bulletin/android-10
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System > Advanced > System update. 2. Install available security updates. 3. Reboot device after installation completes.
🔧 Temporary Workarounds
Disable NFC
androidTurn off NFC functionality to prevent exploitation via malicious NFC tags
Settings > Connected devices > Connection preferences > NFC > Toggle OFF
🧯 If You Can't Patch
- Disable NFC functionality completely in device settings
- Restrict physical access to devices and monitor for unauthorized NFC tags in secure areas
🔍 How to Verify
Check if Vulnerable:
Check Android version: Settings > About phone > Android version = 10 AND Security patch level earlier than 2019-10-01Check Version:
adb shell getprop ro.build.version.release && adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Security patch level is 2019-10-01 or later in Settings > About phone > Android security patch level📡 Detection & Monitoring
Log Indicators:
- Unexpected NFC tag interactions
- Privilege escalation attempts in system logs
- SELinux denials related to NFC service
Network Indicators:
- N/A - Local exploitation only
SIEM Query:
N/A - Requires device-level logging not typically available in SIEM