CVE-2020-25238
📋 TL;DR
This vulnerability allows a local attacker with valid account credentials and limited access rights to manipulate specific files in certain folders, potentially leading to arbitrary code execution with SYSTEM privileges. It affects Siemens PCS neo Administration Console (all versions before V3.1) and TIA Portal (V15, V15.1, V16).
💻 Affected Systems
- Siemens PCS neo Administration Console
- Siemens TIA Portal
📦 What is this software?
Simatic Process Control System Neo by Siemens
View all CVEs affecting Simatic Process Control System Neo →
Totally Integrated Automation Portal by Siemens
View all CVEs affecting Totally Integrated Automation Portal →
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with SYSTEM privileges, allowing complete control over affected systems, data theft, and lateral movement within industrial networks.
Likely Case
Privilege escalation from limited user to SYSTEM, enabling installation of malware, persistence mechanisms, or disruption of industrial processes.
If Mitigated
Limited impact if proper access controls, file integrity monitoring, and least privilege principles are enforced.
🎯 Exploit Status
Exploitation requires local access with valid credentials and knowledge of specific file manipulation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: PCS neo: V3.1 or later; TIA Portal: Update to latest versions beyond affected releases
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-428051.pdf
Restart Required: Yes
Instructions:
1. Download latest version from Siemens support portal. 2. Backup configurations. 3. Install update following vendor documentation. 4. Restart affected systems. 5. Verify installation.
🔧 Temporary Workarounds
Restrict file permissions
windowsApply strict access controls to vulnerable folders to prevent unauthorized file manipulation.
icacls "C:\Program Files\Siemens\PCS neo\*" /deny Users:(OI)(CI)(DE,DC)
icacls "C:\Program Files\Siemens\TIA Portal\*" /deny Users:(OI)(CI)(DE,DC)
Implement least privilege
allRestrict user accounts to minimal necessary permissions and monitor for suspicious file activities.
🧯 If You Can't Patch
- Implement strict access controls and file integrity monitoring on vulnerable directories.
- Segment industrial networks and restrict access to affected systems to authorized personnel only.
🔍 How to Verify
Check if Vulnerable:
Check installed version of Siemens PCS neo or TIA Portal against affected version ranges.Check Version:
Check version in Siemens software interface or Windows Programs and Features.Verify Fix Applied:
Confirm installation of PCS neo V3.1+ or updated TIA Portal versions; verify file permissions on vulnerable directories.📡 Detection & Monitoring
Log Indicators:
- Unauthorized file modifications in Siemens program directories
- Process execution with SYSTEM privileges from unusual locations
Network Indicators:
- Unusual network connections from affected systems to external IPs
SIEM Query:
EventID=4663 OR EventID=4688 AND ProcessName LIKE '%Siemens%' AND IntegrityLevel='System'🔗 References
- https://cert-portal.siemens.com/productcert/pdf/ssa-428051.pdf
- https://us-cert.cisa.gov/ics/advisories/icsa-21-040-05
- https://www.kb.cert.org/vuls/id/466044
- https://cert-portal.siemens.com/productcert/pdf/ssa-428051.pdf
- https://us-cert.cisa.gov/ics/advisories/icsa-21-040-05
- https://www.kb.cert.org/vuls/id/466044
