CVE-2020-12519
📋 TL;DR
This vulnerability in Phoenix Contact PLCnext Control Devices allows unauthenticated attackers to execute arbitrary code with root privileges, potentially opening reverse shells. It affects industrial control systems running versions before 2021.0 LTS, putting critical infrastructure at risk.
💻 Affected Systems
- Phoenix Contact PLCnext Control Devices
📦 What is this software?
Plcnext Firmware by Phoenixcontact
Plcnext Firmware by Phoenixcontact
Plcnext Firmware by Phoenixcontact
Plcnext Firmware by Phoenixcontact
Plcnext Firmware by Phoenixcontact
Plcnext Firmware by Phoenixcontact
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial control system with root access, allowing attackers to manipulate physical processes, disrupt operations, or cause equipment damage.
Likely Case
Unauthorized access to control systems leading to data theft, operational disruption, or installation of persistent backdoors.
If Mitigated
Limited impact if systems are isolated from untrusted networks and have strict access controls, though risk remains from insider threats.
🎯 Exploit Status
Exploitation is straightforward with publicly available tools; no authentication required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2021.0 LTS or later
Vendor Advisory: https://cert.vde.com/en-us/advisories/vde-2020-049
Restart Required: Yes
Instructions:
1. Download PLCnext Engineer 2021.0 LTS or later. 2. Update affected PLCnext Control Devices to firmware version 2021.0 LTS or newer. 3. Restart devices after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate PLCnext devices from untrusted networks using firewalls and VLANs.
Access Control Lists
allImplement strict network access controls to limit connections to authorized IP addresses only.
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable devices from untrusted networks.
- Deploy intrusion detection systems to monitor for exploitation attempts and anomalous behavior.
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via PLCnext Engineer software or web interface; versions before 2021.0 LTS are vulnerable.Check Version:
Use PLCnext Engineer software to read device firmware version or access device web interface at http://<device-ip>/diagnosticsVerify Fix Applied:
Confirm firmware version is 2021.0 LTS or later using PLCnext Engineer or device web interface.📡 Detection & Monitoring
Log Indicators:
- Unexpected process execution, reverse shell connections, unauthorized access attempts to PLCnext services
Network Indicators:
- Unusual outbound connections from PLC devices, unexpected traffic on PLCnext ports (typically 4840, 4841, 4842)
SIEM Query:
source="plcnext" AND (event="process_execution" OR event="network_connection") AND dest_ip NOT IN [authorized_ips]