CVE-2025-40941
📋 TL;DR
SIMATIC CN 4100 devices expose server information in responses, allowing attackers with network access to gather reconnaissance data. This information disclosure vulnerability affects all versions before V4.0.1, potentially enabling more targeted attacks against industrial control systems.
💻 Affected Systems
- SIMATIC CN 4100
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers use disclosed information to identify specific vulnerabilities, leading to full system compromise, production disruption, or safety incidents in industrial environments.
Likely Case
Attackers gather system details to plan targeted attacks, potentially combining with other vulnerabilities for deeper network penetration.
If Mitigated
Limited information exposure with minimal impact due to network segmentation and access controls preventing attacker access.
🎯 Exploit Status
Simple network requests can trigger information disclosure without authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V4.0.1
Vendor Advisory: https://cert-portal.siemens.com/productcert/html/ssa-416652.html
Restart Required: Yes
Instructions:
1. Download firmware V4.0.1 from Siemens support portal. 2. Backup device configuration. 3. Apply firmware update via management interface. 4. Reboot device. 5. Verify version update.
🔧 Temporary Workarounds
Network segmentation
allIsolate SIMATIC CN 4100 devices in protected network segments with strict access controls.
Firewall restrictions
allImplement firewall rules to limit access to SIMATIC CN 4100 management interfaces to authorized IPs only.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate devices from untrusted networks
- Deploy intrusion detection systems to monitor for reconnaissance attempts
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or CLI. If version is below V4.0.1, device is vulnerable.Check Version:
Check via web interface at https://[device-ip] or consult device documentation for CLI commandsVerify Fix Applied:
Confirm firmware version shows V4.0.1 or higher in device management interface.📡 Detection & Monitoring
Log Indicators:
- Unusual access patterns to device management interfaces
- Multiple failed authentication attempts
Network Indicators:
- Unusual HTTP requests to device endpoints
- Reconnaissance traffic from unauthorized sources
SIEM Query:
source_ip NOT IN (authorized_ips) AND dest_ip IN (simatic_devices) AND (http_method=GET OR http_method=POST)