CVE-2017-13314
📋 TL;DR
This vulnerability allows local attackers to bypass VPN network restrictions on Android devices. A missing permission check in the NetworkManagementService lets users access non-VPN networks when they should be restricted to VPN traffic only. This affects Android devices with VPN configurations that restrict network access.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker with local access could bypass VPN restrictions to access internal corporate networks, potentially exposing sensitive data or systems that should only be accessible through the VPN tunnel.
Likely Case
Malicious apps or users could bypass VPN restrictions to access local network resources or the internet directly when they should be forced through VPN, potentially leaking data outside the secure tunnel.
If Mitigated
With proper VPN configuration and device management, the impact is limited to potential data leakage rather than full system compromise.
🎯 Exploit Status
Exploitation requires local access to the device but no user interaction. The vulnerability is in system services, making exploitation straightforward for attackers with app installation privileges.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level 2018-05-01 or later
Vendor Advisory: https://source.android.com/security/bulletin/2018-05-01
Restart Required: Yes
Instructions:
1. Apply the May 2018 Android security patch. 2. Update affected Android devices to security patch level 2018-05-01 or later. 3. For enterprise devices, push updates through MDM solutions. 4. Verify patch installation by checking security patch level in Settings > About phone.
🔧 Temporary Workarounds
Disable VPN-only mode
androidRemove VPN configurations that restrict network access to VPN-only mode, using split tunneling instead.
Restrict app installation
androidPrevent installation of untrusted apps that could exploit this vulnerability.
🧯 If You Can't Patch
- Monitor for unusual network traffic patterns indicating VPN bypass
- Implement network segmentation to limit damage if VPN restrictions are bypassed
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone. If patch level is earlier than 2018-05-01 and device is running Android 8.0 or 8.1, it is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level shows 2018-05-01 or later in Settings > About phone.📡 Detection & Monitoring
Log Indicators:
- Network traffic from VPN-restricted devices bypassing VPN tunnel
- Unexpected network interface activations on VPN devices
Network Indicators:
- Direct internet access from devices that should only have VPN access
- Traffic from VPN IP ranges appearing from non-VPN sources
SIEM Query:
source_ip IN (vpn_device_ips) AND NOT destination_ip IN (vpn_gateway_ips)