CVE-2020-12828
📋 TL;DR
This vulnerability allows local attackers to execute arbitrary code with SYSTEM privileges by exploiting the AnchorFree VPN SDK service. The service accepts executable paths over a local socket, enabling privilege escalation. Any system running vulnerable versions of AnchorFree VPN SDK is affected.
💻 Affected Systems
- AnchorFree VPN SDK
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full SYSTEM-level compromise of the host, allowing complete control over the system, data theft, persistence installation, and lateral movement.
Likely Case
Local privilege escalation leading to SYSTEM-level code execution, enabling attackers to bypass security controls and install malware.
If Mitigated
Limited impact if proper network segmentation and least privilege principles are enforced, though local attackers could still escalate privileges.
🎯 Exploit Status
Exploitation requires local access but is straightforward once access is obtained. The vulnerability is well-documented in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.3.3.218 and later
Vendor Advisory: https://www.pango.co/sec31944/
Restart Required: Yes
Instructions:
1. Update AnchorFree VPN SDK to version 1.3.3.218 or later. 2. Update any applications using the SDK. 3. Restart affected services or systems.
🔧 Temporary Workarounds
Disable VPN SDK service
windowsTemporarily disable the vulnerable VPN SDK service if patching is not immediately possible.
sc stop "AnchorFree VPN SDK Service"
sc config "AnchorFree VPN SDK Service" start= disabled
Restrict local socket access
windowsApply firewall rules to restrict access to the local socket used by the VPN SDK service.
netsh advfirewall firewall add rule name="Block VPN SDK Socket" dir=in action=block protocol=TCP localport=LOCAL_SOCKET_PORT
🧯 If You Can't Patch
- Implement strict network segmentation to limit lateral movement from compromised systems.
- Apply least privilege principles and monitor for suspicious local privilege escalation attempts.
🔍 How to Verify
Check if Vulnerable:
Check the version of AnchorFree VPN SDK installed. If version is below 1.3.3.218, the system is vulnerable.Check Version:
Check application manifest or SDK documentation for version information. On Windows, check installed programs list or service properties.Verify Fix Applied:
Verify that AnchorFree VPN SDK version is 1.3.3.218 or higher after update.📡 Detection & Monitoring
Log Indicators:
- Unusual process execution from non-standard paths with SYSTEM privileges
- Failed attempts to bind to local VPN SDK socket
Network Indicators:
- Unexpected local socket connections to VPN SDK service port
SIEM Query:
Process Creation where Parent Process contains "AnchorFree" AND Integrity Level = "System"