CVE-2025-41729
📋 TL;DR
An unauthenticated remote attacker can send a specially crafted Modbus read command to vulnerable devices, causing a denial of service. This affects industrial control systems and IoT devices using Modbus protocol. Organizations with exposed Modbus-enabled devices are at risk.
💻 Affected Systems
- Industrial control systems
- IoT devices
- SCADA systems
- PLC devices
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Critical industrial processes disrupted, production halted, safety systems disabled leading to physical damage or safety incidents.
Likely Case
Device becomes unresponsive requiring manual reboot, causing temporary operational disruption in industrial environments.
If Mitigated
Minimal impact with proper network segmentation and access controls preventing external attackers from reaching Modbus interfaces.
🎯 Exploit Status
Exploitation requires network access to Modbus port (typically TCP 502). No authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown - Check specific vendor advisories
Vendor Advisory: https://certvde.com/de/advisories/VDE-2025-094
Restart Required: Yes
Instructions:
1. Check vendor website for firmware updates. 2. Download latest firmware. 3. Backup configuration. 4. Apply firmware update following vendor instructions. 5. Verify functionality after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Modbus devices in separate network segments with strict firewall rules
Access Control Lists
linuxRestrict Modbus port (TCP 502) access to authorized IP addresses only
iptables -A INPUT -p tcp --dport 502 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 502 -j DROP
🧯 If You Can't Patch
- Implement network segmentation to isolate Modbus devices from untrusted networks
- Deploy intrusion detection systems to monitor for malicious Modbus traffic patterns
🔍 How to Verify
Check if Vulnerable:
Test by sending crafted Modbus read commands to port 502 and observing device response. Use tools like modbus-cli or custom scripts.Check Version:
Vendor-specific - typically through web interface, serial console, or vendor management softwareVerify Fix Applied:
After patching, attempt the same exploit and verify device remains responsive. Monitor system logs for stability.📡 Detection & Monitoring
Log Indicators:
- Device crash/restart logs
- Modbus protocol errors
- Unusual connection attempts to port 502
Network Indicators:
- Malformed Modbus packets
- High volume of Modbus requests from single source
- Traffic to port 502 from unauthorized sources
SIEM Query:
source_port=502 AND (packet_size>normal OR protocol_violation=true) OR dest_port=502 AND rate_threshold_exceeded