ICS Advisory (ICSA-17-136-02)

Schneider Electric SoMachine HVAC

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CVSS v3 7.8

ATTENTION: Low skill level to exploit

Vendor: Schneider Electric

Equipment: SoMachine HVAC

Vulnerabilities: Buffer Overflow, DLL Hijack


The following version of SoMachine HVAC, a PLC programming software, is affected:

  • SoMachine HVAC Versions 2.1.0 and prior.


Successful exploitation of these vulnerabilities may allow arbitrary code execution and could cause the device that the attacker is accessing to crash due to a buffer overflow condition.


Schneider Electric recommends that users of SoMachine HVAC Programming Software update to SoMachine HVAC v2.2. Users of SoMachine HVAC can access the update at the following support web site:

http://www.schneider-electric.com/en/download/document/SoMachine HVAC - Programming Software for Modicon M171-M172 Logic Controllers/

Schneider Electric’s security notice SEVD-2017-125-01 is available at the following location:


Schneider Electric’s security notice SEVD-2017-125-02 is available at the following location:


NCCIC/ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should:

  • Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
  • Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
  • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

ICS-CERT 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 in the ICS‑CERT Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site.

Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to ICS-CERT for tracking and correlation against other incidents.

In addition, ICS-CERT recommends that users take the following measures to protect themselves from social engineering attacks:

  1. Do not click web links or open unsolicited attachments in email messages.
  2. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
  3. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploits specifically target these vulnerabilities. These vulnerabilities are not remotely exploitable.


AlTracePrint.exe, installed by SoMachine HVAC v2.1.0 Programming Software, could be called in a way that could lead to a buffer overflow.

CVE-2017-7965 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been assigned; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

Improper loading of a DLL file could allow an unauthenticated attacker the ability to execute arbitrary code on the target system.

CVE-2017-7966 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been assigned; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).


Independent researcher Zhou YU reported the buffer overflow vulnerability to ICS-CERT. Schneider Electric reported to ICS-CERT that security researcher Himanshu Mehta disclosed the DLL Hijack vulnerability to them.


Critical Infrastructure Sectors: Critical Manufacturing, Dams, Defense Industrial Base, Energy, Food and Agriculture, Government Facilities, Nuclear Reactors, Materials, and Waste, Transportation Systems, Water and Wastewater Systems

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Paris, France

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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