All information products included in https://us-cert.cisa.gov/ics are provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained within. DHS does not endorse any commercial product or service, referenced in this product or otherwise. Further dissemination of this product is governed by the Traffic Light Protocol (TLP) marking in the header. For more information about TLP, see https://us-cert.cisa.gov/tlp/.
1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: SIMATIC WinCC OA
- Vulnerability: Use of Client-side Authentication
CISA is aware of a public report, known as “OT:ICEFALL” that details vulnerabilities found in multiple operational technology (OT) vendors. CISA is issuing this advisory to provide notice of the reported vulnerabilities and identify baseline mitigations for reducing risks to these and other cybersecurity attacks.
2. RISK EVALUATION
Successful exploitation of this vulnerability could allow an attacker to impersonate other users or exploit the client-server protocol without being authenticated.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following versions of SIMATIC WinCC OA, a SCADA HMI system, are affected:
- SIMATIC WinCC OA v3.16: All versions
- SIMATIC WinCC OA v3.17: All versions
- SIMATIC WinCC OA v3.18: All versions
3.2 VULNERABILITY OVERVIEW
Affected applications use client-side only authentication when neither server-side authentication nor Kerberos authentication is enabled. In this configuration, attackers could impersonate other users or exploit the client-server protocol without being authenticated.
• CRITICAL INFRASTRUCTURE SECTORS: Multiple Sectors
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Germany
Daniel dos Santos and Jos Wetzels from Forecout Technologies reported this vulnerability to CISA.
Siemens recommends the following mitigations or workarounds:
- Enable server-side authentication (SSA) or Kerberos authentication for your WinCC OA project (login required).
As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for industrial security and following recommendations in the product manuals.
For additional information, please refer to Siemens Security Advisory SSA-111512
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on cisa.gov/ics in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability.
For any questions related to this report, please contact the CISA at:
Toll Free: 1-888-282-0870
CISA continuously strives to improve its products and services. You can help by choosing one of the links below to provide feedback about this product.
Please share your thoughts.
We recently updated our anonymous product survey; we'd welcome your feedback.