CVE-2020-12504
📋 TL;DR
This CVE describes an improper authorization vulnerability in Pepperl+Fuchs Comtrol RocketLinx industrial switches that allows attackers to bypass authentication and execute arbitrary commands via the active TFTP service. Affected organizations include industrial control systems, manufacturing facilities, and critical infrastructure using these specific switch models.
💻 Affected Systems
- Pepperl+Fuchs P+F Comtrol RocketLinx ES7510-XT
- ES8509-XT
- ES8510-XT
- ES9528-XTv2
- ES7506
- ES7510
- ES7528
- ES8508
- ES8508F
- ES8510
- ES8510-XTE
- ES9528/ES9528-XT
- ICRL-M-8RJ45/4SFP-G-DIN
- ICRL-M-16RJ45/4CP-G-DIN
📦 What is this software?
Es7506 Firmware by Pepperl Fuchs
Es7510 Firmware by Pepperl Fuchs
Es7510 Xt Firmware by Pepperl Fuchs
Es7528 Firmware by Pepperl Fuchs
Es8508 Firmware by Pepperl Fuchs
Es8508f Firmware by Pepperl Fuchs
Es8509 Xt Firmware by Pepperl Fuchs
Es8510 Firmware by Pepperl Fuchs
Es8510 Xt Firmware by Pepperl Fuchs
Es8510 Xte Firmware by Pepperl Fuchs
Es9528 Firmware by Pepperl Fuchs
Es9528 Xt Firmware by Pepperl Fuchs
Es9528 Xtv2 Firmware by Pepperl Fuchs
Icrl M 16rj45\/4cp G Din Firmware by Pepperl Fuchs
Icrl M 8rj45\/4sfp G Din Firmware by Pepperl Fuchs
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial network, unauthorized command execution leading to operational disruption, data exfiltration, or physical damage to connected industrial equipment.
Likely Case
Unauthorized access to network devices, configuration changes, network disruption, and potential lateral movement to other industrial control systems.
If Mitigated
Limited impact with proper network segmentation, but still poses risk to isolated industrial networks if exploited internally.
🎯 Exploit Status
Exploitation requires only network access to TFTP service (UDP port 69) with no authentication. Public exploit code and detailed analysis available in referenced advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific firmware updates
Vendor Advisory: https://cert.vde.com/en-us/advisories/vde-2020-053
Restart Required: Yes
Instructions:
1. Download latest firmware from Pepperl+Fuchs support portal. 2. Backup current configuration. 3. Upload new firmware via web interface or TFTP. 4. Reboot device. 5. Restore configuration if needed. 6. Verify firmware version.
🔧 Temporary Workarounds
Disable TFTP Service
allDisable the vulnerable TFTP service if not required for operations
Access device web interface -> System -> Services -> Disable TFTP
Network Access Control
allRestrict network access to TFTP service (UDP 69) using firewall rules
iptables -A INPUT -p udp --dport 69 -j DROP
netsh advfirewall firewall add rule name="Block TFTP" dir=in action=block protocol=UDP localport=69
🧯 If You Can't Patch
- Segment affected devices in isolated VLAN with strict access controls
- Implement network monitoring for TFTP traffic and unauthorized access attempts
🔍 How to Verify
Check if Vulnerable:
Attempt TFTP connection to device UDP port 69: 'tftp <device_ip> get /etc/passwd' or use nmap: 'nmap -sU -p 69 --script tftp-enum <device_ip>'Check Version:
Login to web interface and check System -> Firmware version, or SSH/Telnet and use 'show version' commandVerify Fix Applied:
Verify TFTP service is disabled or patched by attempting same connection methods that should fail, and check firmware version matches patched release📡 Detection & Monitoring
Log Indicators:
- TFTP service access logs showing unauthorized connections
- Configuration change logs without authorized user activity
- Unexpected device reboots or service restarts
Network Indicators:
- TFTP traffic to industrial network devices
- Unexpected UDP port 69 connections from unauthorized sources
- Anomalous traffic patterns to switch management interfaces
SIEM Query:
source="network_firewall" dest_port=69 protocol=UDP action=allow | stats count by src_ip dest_ip🔗 References
- http://packetstormsecurity.com/files/162903/Korenix-CSRF-Backdoor-Accounts-Command-Injection-Missing-Authentication.html
- http://packetstormsecurity.com/files/165875/Korenix-Technology-JetWave-CSRF-Command-Injection-Missing-Authentication.html
- http://seclists.org/fulldisclosure/2021/Jun/0
- https://cert.vde.com/de-de/advisories/vde-2020-040
- https://cert.vde.com/en-us/advisories/vde-2020-053
- https://sec-consult.com/vulnerability-lab/advisory/multiple-critical-vulnerabilities-in-korenix-technology-westermo-pepperl-fuchs/
- http://packetstormsecurity.com/files/162903/Korenix-CSRF-Backdoor-Accounts-Command-Injection-Missing-Authentication.html
- http://packetstormsecurity.com/files/165875/Korenix-Technology-JetWave-CSRF-Command-Injection-Missing-Authentication.html
- http://seclists.org/fulldisclosure/2021/Jun/0
- https://cert.vde.com/de-de/advisories/vde-2020-040
- https://cert.vde.com/en-us/advisories/vde-2020-053
- https://sec-consult.com/vulnerability-lab/advisory/multiple-critical-vulnerabilities-in-korenix-technology-westermo-pepperl-fuchs/
