CVE-2020-25196
📋 TL;DR
The built-in WEB server in MOXA NPort IAW5000A-I/O firmware version 2.1 or lower allows SSH/Telnet sessions that can be brute-forced to bypass authentication. This affects industrial control systems using these specific MOXA devices with vulnerable firmware. Attackers can gain unauthorized access to critical industrial network equipment.
💻 Affected Systems
- MOXA NPort IAW5000A-I/O
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of industrial control system allowing attackers to manipulate I/O operations, disrupt industrial processes, or pivot to other critical systems.
Likely Case
Unauthorized access to device configuration leading to network disruption, data exfiltration, or device manipulation.
If Mitigated
Limited impact with proper network segmentation and access controls preventing exploitation attempts.
🎯 Exploit Status
Brute force attacks require no authentication and can be automated with common tools like Hydra or Metasploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware version 2.2 or higher
Vendor Advisory: https://www.moxa.com/en/support/product-support/security-advisory/mpsa-200301-nport-iaw5000a-io-series-web-server-vulnerability
Restart Required: Yes
Instructions:
1. Download firmware version 2.2 or higher from MOXA website. 2. Backup current configuration. 3. Upload new firmware via web interface. 4. Reboot device. 5. Restore configuration if needed.
🔧 Temporary Workarounds
Disable SSH/Telnet on WEB server
allDisable SSH and Telnet services on the built-in WEB server interface
Login to web interface > System > Network Services > Disable SSH and Telnet
Implement network access controls
linuxRestrict access to device management interfaces using firewall rules
iptables -A INPUT -p tcp --dport 22 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable devices
- Deploy intrusion detection systems to monitor for brute force attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface: System > About. If version is 2.1 or lower, device is vulnerable.Check Version:
ssh admin@device_ip 'show version' or check web interface System > About pageVerify Fix Applied:
After patching, verify firmware version shows 2.2 or higher and attempt SSH/Telnet connection should fail or require proper authentication.📡 Detection & Monitoring
Log Indicators:
- Multiple failed SSH/Telnet authentication attempts from single source
- Successful login after many failed attempts
Network Indicators:
- High volume of SSH/Telnet connection attempts to port 22/23
- Traffic patterns matching brute force tools
SIEM Query:
source="device_logs" (event="authentication failed" OR event="login failed") | stats count by src_ip dest_ip | where count > 10