CVE-2018-9391
📋 TL;DR
This vulnerability allows local privilege escalation on Android devices with MediaTek GPS chipsets. An attacker with system execution privileges can exploit an out-of-bounds write in GPS handling code to gain elevated privileges. Only devices with specific MediaTek hardware and vulnerable Android versions are affected.
💻 Affected Systems
- Android devices with MediaTek GPS chipsets
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attacker to execute arbitrary code with system privileges, potentially installing persistent malware or accessing sensitive data.
Likely Case
Local privilege escalation allowing malware or malicious apps to gain system-level access and bypass security controls.
If Mitigated
Limited impact if devices are patched or have proper app sandboxing and privilege separation in place.
🎯 Exploit Status
Requires system execution privileges to exploit; no user interaction needed but initial access required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: June 2018 Android Security Patch Level or later
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2018-06-01
Restart Required: Yes
Instructions:
1. Apply June 2018 Android security patch. 2. Update device firmware through manufacturer channels. 3. Reboot device after update.
🔧 Temporary Workarounds
Disable GPS services
androidTemporarily disable GPS functionality to prevent exploitation of vulnerable code paths
adb shell pm disable com.android.location.fused
adb shell pm disable com.android.location.gps
🧯 If You Can't Patch
- Restrict installation of untrusted applications to reduce attack surface
- Implement strict app sandboxing and monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level: Settings > About phone > Android security patch level. If before June 2018, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android security patch level shows June 2018 or later. Check GPS functionality works normally after patch.📡 Detection & Monitoring
Log Indicators:
- Unusual GPS service crashes
- Privilege escalation attempts in system logs
- SELinux denials related to GPS services
Network Indicators:
- None - local exploitation only
SIEM Query:
source="android_system" AND (event="gps_crash" OR event="privilege_escalation")