CVE-2025-27394
📋 TL;DR
This vulnerability allows an authenticated, highly-privileged remote attacker to execute arbitrary code on affected SCALANCE LPE9403 devices by exploiting improper input sanitization when creating new SNMP users. It affects all versions of SCALANCE LPE9403 (6GK5998-3GS00-2AC2) prior to V4.0. Organizations using these devices in industrial or network environments are at risk.
💻 Affected Systems
- SCALANCE LPE9403 (6GK5998-3GS00-2AC2)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise leading to disruption of industrial operations, data theft, or lateral movement into connected networks.
Likely Case
Unauthorized code execution allowing attacker control over the device for reconnaissance or further attacks.
If Mitigated
Limited impact if strong access controls and network segmentation are in place, reducing exposure.
🎯 Exploit Status
Exploitation requires authenticated, highly-privileged access, making it less trivial but feasible for skilled attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V4.0 or later
Vendor Advisory: https://cert-portal.siemens.com/productcert/html/ssa-075201.html
Restart Required: No
Instructions:
1. Download firmware version V4.0 or later from Siemens support portal. 2. Follow vendor instructions to update the device firmware. 3. Verify the update completes successfully without errors.
🔧 Temporary Workarounds
Restrict SNMP User Creation
allDisable or limit SNMP user creation functionality to reduce attack surface.
Configure device settings to disable unnecessary SNMP features via vendor CLI or web interface.
🧯 If You Can't Patch
- Implement strict access controls to limit who can authenticate and create SNMP users.
- Segment network to isolate affected devices and monitor for suspicious SNMP activity.
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or CLI; if version is < V4.0, it is vulnerable.Check Version:
Use vendor-specific command (e.g., via SSH or web interface) to display firmware version; consult Siemens documentation for exact syntax.Verify Fix Applied:
After updating, confirm firmware version is V4.0 or higher and test SNMP user creation for proper input validation.📡 Detection & Monitoring
Log Indicators:
- Unusual SNMP user creation events, failed authentication attempts, or unexpected command executions in device logs.
Network Indicators:
- Suspicious SNMP traffic patterns or connections from unauthorized IP addresses.
SIEM Query:
Example: 'source="SCALANCE" AND event_type="SNMP_user_creation" AND status="success"'