CVE-2025-27396
📋 TL;DR
A privilege escalation vulnerability in Siemens SCALANCE LPE9403 industrial routers allows authenticated low-privileged remote attackers to gain higher privileges. This affects all versions before V4.0 of the SCALANCE LPE9403 (6GK5998-3GS00-2AC2) device. Attackers could potentially gain administrative control over the industrial network device.
💻 Affected Systems
- Siemens SCALANCE LPE9403 (6GK5998-3GS00-2AC2)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An attacker gains full administrative control of the industrial router, enabling network traffic interception, configuration changes, or using the device as a pivot point to attack other industrial systems.
Likely Case
An authenticated attacker with low privileges escalates to administrative privileges, allowing them to modify network configurations, disrupt industrial communications, or install persistent backdoors.
If Mitigated
With proper network segmentation and access controls, the impact is limited to the affected device only, preventing lateral movement to critical industrial systems.
🎯 Exploit Status
Requires authenticated access with low privileges. No public exploit code is currently available.
🛠️ 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 Industrial Network Support. 2. Backup current device configuration. 3. Upload and install the new firmware via the web interface or management tools. 4. Verify the firmware version after installation.
🔧 Temporary Workarounds
Restrict network access
allLimit network access to the SCALANCE management interface to only trusted administrative networks using firewall rules.
Implement strong authentication
allUse complex passwords and consider implementing multi-factor authentication if supported to reduce the risk of credential compromise.
🧯 If You Can't Patch
- Segment the industrial network to isolate the SCALANCE device from critical systems
- Implement strict access controls and monitor all authentication attempts to the device
🔍 How to Verify
Check if Vulnerable:
Check the firmware version in the device web interface under System Information or via CLI using 'show version' command.Check Version:
show versionVerify Fix Applied:
Verify the firmware version shows V4.0 or later in the device management interface.📡 Detection & Monitoring
Log Indicators:
- Multiple privilege escalation attempts in authentication logs
- Unusual administrative actions from non-admin accounts
- Configuration changes from unexpected user accounts
Network Indicators:
- Unusual management traffic patterns to the SCALANCE device
- Administrative protocol traffic from non-admin network segments
SIEM Query:
source="scalance-logs" AND (event_type="privilege_escalation" OR user_role_change="true")