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Siemens Simatic HMI Authentication Vulnerabilities

Low RiskICS-CERT ICSA-11-356-01Sep 24, 2011
Summary

SIMATIC WinCC flexible RT, WinCC Runtime Advanced, and SIMATIC Panels contain authentication bypass vulnerabilities (CWE-287, CWE-1392) that allow an attacker on the network to log in without valid credentials and access the human-machine interface. Affected versions are WinCC flexible RT 2004–2008 SP2, WinCC Runtime Advanced 11–11 SP2, and SIMATIC TP/OP/MP/Mobile/Comfort Panels. No vendor patches are available for these products. Siemens recommends implementing network controls and monitoring to limit exposure.

What this means
What could happen
An attacker with network access to a SIMATIC HMI could bypass authentication mechanisms and gain unauthorized access to control the human-machine interface, potentially allowing them to modify process parameters, trigger alarms, or manipulate operator displays without credentials.
Who's at risk
Manufacturing operations relying on Siemens SIMATIC HMI systems for process control and monitoring, including plant operators, automation engineers, and system integrators. Affected equipment includes SIMATIC WinCC flexible RT (2004–2008 SP2), WinCC Runtime Advanced (version 11 series), and SIMATIC Comfort and Mobile Panels, which are common in water treatment, chemical processing, and power generation facilities.
How it could be exploited
An attacker on the network sends specially crafted authentication requests to the SIMATIC HMI (WinCC flexible RT, WinCC Runtime Advanced, or SIMATIC Panels). Due to flawed authentication logic (CWE-287), the device accepts the requests without proper credential validation, allowing the attacker to log in and issue commands to alter the running process or suppress alarms.
Prerequisites
  • Network reachability to the HMI device on its HTTP/Ethernet interface
  • Knowledge of the device type and version running on the target network
  • No valid engineering credentials required for exploitation
Remotely exploitableNo authentication requiredNo patch available (end-of-life products)Affects operator control systemsLow EPSS score limits urgency but does not eliminate risk
Exploitability
Moderate exploit probability (EPSS 1.2%)
Affected products (3)
1 pending2 EOL
ProductAffected VersionsFix Status
Multiple SIMATIC Panels: TP_OP_MP_Mobile_and_ComfortTP OP MP Mobile and ComfortNo fix yet
SIMATIC WinCC flexible RT: 2004|2005|2005|SP1|2007|2008|2008|SP1|2008|SP22004|2005|2005|SP1|2007|2008|2008|SP1|2008|SP2No fix (EOL)
SIMATIC WinCC Runtime Advanced: 11|11|SP1|11|SP211|11|SP1|11|SP2No fix (EOL)
Remediation & Mitigation
0/5
Do now
0/3
HARDENINGImplement network segmentation to restrict access to SIMATIC HMI devices to authorized engineering workstations and control systems only
WORKAROUNDDeploy firewall rules to block unauthorized access to HMI ports (typically 80, 443, and vendor-specific control ports)
WORKAROUNDDisable or restrict remote access to HMI devices if not operationally required
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HARDENINGMonitor network traffic to SIMATIC HMI devices for authentication anomalies or unexpected commands
Mitigations - no patch available
0/1
The following products have reached End of Life with no planned fix: SIMATIC WinCC flexible RT: 2004|2005|2005|SP1|2007|2008|2008|SP1|2008|SP2, SIMATIC WinCC Runtime Advanced: 11|11|SP1|11|SP2. Apply the following compensating controls:
HARDENINGDocument and maintain an inventory of all SIMATIC WinCC and HMI systems to prioritize network protection
View full CISA ICS-CERT advisory
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