CVE-2025-27393
📋 TL;DR
This vulnerability in Siemens SCALANCE LPE9403 industrial network devices allows authenticated high-privileged attackers to execute arbitrary code due to improper input sanitization during user creation. It affects all versions before V4.0 of the SCALANCE LPE9403 (6GK5998-3GS00-2AC2) device. Attackers need administrative credentials to exploit this flaw.
💻 Affected Systems
- Siemens SCALANCE LPE9403 (6GK5998-3GS00-2AC2)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to execute arbitrary code, potentially disrupting industrial operations, stealing sensitive data, or using the device as a pivot point into industrial control systems.
Likely Case
Privileged attackers gaining persistent access to the device, modifying configurations, and potentially disrupting network connectivity for connected industrial equipment.
If Mitigated
Limited impact due to proper access controls, network segmentation, and monitoring preventing unauthorized administrative access.
🎯 Exploit Status
Exploitation requires administrative credentials. The vulnerability is in user creation functionality where input isn't properly sanitized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V4.0
Vendor Advisory: https://cert-portal.siemens.com/productcert/html/ssa-075201.html
Restart Required: No
Instructions:
1. Download firmware version V4.0 from Siemens support portal. 2. Backup current configuration. 3. Upload and install the new firmware via web interface or management tools. 4. Verify installation and restore configuration if needed.
🔧 Temporary Workarounds
Restrict administrative access
allLimit administrative access to trusted IP addresses and users only. Implement strong authentication controls.
Disable unnecessary user creation
allIf user creation functionality is not required, restrict or disable it through configuration.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate SCALANCE devices from untrusted networks
- Enforce strong password policies and multi-factor authentication for administrative accounts
- Monitor for suspicious user creation activities and failed authentication attempts
- Regularly audit administrative access logs and user accounts
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or CLI. If version is below V4.0, the device is vulnerable.Check Version:
Check via web interface: System > Device Information > Firmware VersionVerify Fix Applied:
After updating, verify firmware version shows V4.0 or higher in device management interface.📡 Detection & Monitoring
Log Indicators:
- Unusual user creation events
- Multiple failed authentication attempts followed by successful admin login
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from SCALANCE device
- Traffic patterns inconsistent with normal industrial operations
SIEM Query:
source="scalance_logs" AND (event_type="user_creation" OR auth_result="success" AND user_role="admin")