ICS Advisory (ICSA-18-109-01)

Siemens SIMATIC WinCC OA Operator IOS App (Update A)

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  • CVSS v3 4.0
  • Vendor: Siemens
  • Equipment: SIMATIC WinCC OA iOS App
  • Vulnerability: File and Directory Information Exposure.


This updated advisory is a follow-up to the original advisory titled ICSA-18-109-01 Siemens SIMATIC WinCC OA Operator iOS App that was published April 19, 2018, on the NCCIC/ICS-CERT.


Successful exploitation of this vulnerability could allow an attacker with physical access to read sensitive data located in the app’s directory.



--------- Begin Update A Part 1 of 2 --------

Siemens reports this vulnerability affects the following product:

  • SIMATIC WinCC OA Operator iOS App: All versions prior to v1.4.
--------- End Update A Part 1 of 2 ----------


An attacker with physical access to the mobile device could read unencrypted sensitive data from the app’s directory.

CVE-2018-4847 has been assigned to this vulnerability. A CVSS v3 base score of 4.0 has been calculated; the CVSS vector string is (AV:P/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N).


  • Critical Infrastructure Sectors: Chemical, Energy, Food and Agriculture, and Water and Wastewater Systems
  • Countries/Areas Deployed: Worldwide
  • Company Headquarters Location: Germany


Alexander Bolshev of IOActive and Ivan Yushkevich of Embedi reported this vulnerability to Siemens.


--------- Begin Update A Part 2 of 2 --------

Siemens has recommended that users update to v1.4, which can be located here:


--------- End Update A Part 2 of 2 ----------

Siemens has identified the following specific workarounds and mitigations that users can apply to reduce the risk:

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and following the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity

For more information on this vulnerability and associated mitigation practices, please see Siemens security advisory SSA-597741 on their website:


NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

NCCIC also provides a section for control systems security recommended practices on the ICS-CERT web page. 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-CERT website 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 NCCIC for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely. High skill level is needed to exploit.

Contact Information

For any questions related to this report, please contact the CISA at:

Email: CISAservicedesk@cisa.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:  https://us-cert.cisa.gov/ics 
or incident reporting:  https://us-cert.cisa.gov/report

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