CVE-2020-15786
📋 TL;DR
This vulnerability allows remote attackers to perform brute-force attacks against SIMATIC HMI panels due to insufficient authentication attempt blocking. Attackers could discover user passwords and gain access to the Sm@rt Server. Affected devices include various SIMATIC HMI panel models running vulnerable firmware versions.
💻 Affected Systems
- SIMATIC HMI Basic Panels 2nd Generation
- SIMATIC HMI Comfort Panels
- SIMATIC HMI Mobile Panels
- SIMATIC HMI Unified Comfort Panels
📦 What is this software?
Simatic Hmi Basic Panels 2nd Generation Firmware by Siemens
View all CVEs affecting Simatic Hmi Basic Panels 2nd Generation Firmware →
Simatic Hmi Comfort Panels Firmware by Siemens
View all CVEs affecting Simatic Hmi Comfort Panels Firmware →
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of HMI panels allowing attackers to manipulate industrial processes, steal sensitive data, or disrupt operations.
Likely Case
Unauthorized access to HMI interfaces leading to data theft, configuration changes, or operational disruption.
If Mitigated
Limited impact with proper network segmentation and monitoring, though authentication bypass remains possible.
🎯 Exploit Status
Brute-force attacks require no authentication and use standard tools. Attack complexity is minimal.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V16 or later
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-542525.pdf
Restart Required: Yes
Instructions:
1. Download firmware update V16 or later from Siemens support portal. 2. Backup current configuration. 3. Apply firmware update following Siemens documentation. 4. Restart affected panels. 5. Verify successful update.
🔧 Temporary Workarounds
Network segmentation and access control
allRestrict network access to HMI panels using firewalls and VLANs to limit exposure.
Strong password policy
allImplement complex passwords to increase brute-force resistance time.
🧯 If You Can't Patch
- Implement network-level rate limiting for authentication attempts
- Deploy intrusion detection systems to monitor for brute-force patterns
🔍 How to Verify
Check if Vulnerable:
Check firmware version on HMI panel via control panel or Siemens TIA Portal.Check Version:
Check via Siemens TIA Portal or panel display settings.Verify Fix Applied:
Confirm firmware version is V16 or later and test authentication attempt blocking.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts from single IP
- Successful logins after many failures
Network Indicators:
- High volume of authentication requests to HMI panels
- Traffic patterns matching brute-force tools
SIEM Query:
source_ip=* AND (event_type="authentication_failure" OR event_type="login_failed") COUNT > 10 WITHIN 5min