CVE-2018-9417
📋 TL;DR
This vulnerability allows local attackers to escalate privileges on Android devices through a use-after-free bug in the USB HID gadget driver. It affects Android devices running vulnerable kernel versions, requiring physical or local access to the device. No user interaction is needed for exploitation.
💻 Affected Systems
- Android devices
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise with root privileges, allowing installation of persistent malware, data theft, and bypassing all security controls.
Likely Case
Local privilege escalation to root, enabling attackers to bypass app sandboxing, access sensitive data, and modify system files.
If Mitigated
Limited impact if devices are fully patched and have SELinux/AppArmor properly configured to restrict kernel module loading.
🎯 Exploit Status
Exploitation requires local access and knowledge of kernel memory layout. Multiple proof-of-concept exploits have been published.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android security patch level July 2018 or later
Vendor Advisory: https://source.android.com/security/bulletin/2018-07-01
Restart Required: Yes
Instructions:
1. Apply July 2018 Android security patch via OTA update or manual flash. 2. Reboot device. 3. Verify patch level in Settings > About phone > Android security patch level.
🔧 Temporary Workarounds
Disable USB debugging
androidPrevents unauthorized USB connections that could be used to trigger the vulnerability
adb shell settings put global adb_enabled 0
Restrict USB access
androidLimit USB connections to trusted devices only through MDM policies
🧯 If You Can't Patch
- Implement strict physical security controls to prevent unauthorized device access
- Use mobile device management (MDM) to enforce security policies and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone. If before July 2018, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify Android security patch level shows July 2018 or later. Check kernel version with 'uname -r' and ensure it's patched.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- USB HID gadget driver crash logs
- SELinux denials related to f_hid.c
Network Indicators:
- Unusual USB connection patterns
- Unexpected ADB connections
SIEM Query:
source="android_kernel" AND ("f_hid" OR "hidg" OR "use-after-free")