ATTENTION: Exploitable from an adjacent network/low skill level to exploit.
Equipment: Devices using the PROFINET Discovery and Configuration Protocol (DCP)
Vulnerability: Denial of Service
This updated advisory is a follow-up to the updated advisory titled ICSA-17-129-01G Siemens devices using the PROFINET Discovery and Configuration Protocol that was published November 14, 2017, on the NCCIC/ICS-CERT web site.
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Siemens reports that the vulnerability affects the following products using the PROFINET DCP:
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An attacker may be able to cause a denial-of-service condition requiring a manual restart by exploiting this vulnerability.
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Siemens provides updates that fix the vulnerability for the following affected products and recommends that users update to the new fixed version:
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The affected component is shared among all of the affected products on the host. Installing one fixed version will mitigate the vulnerability for all Siemens applications installed on that host.
Siemens is preparing updates for the remaining affected products and recommends the following mitigations in the meantime:
As a general security measure, Siemens strongly recommends protecting industrial control systems networks with appropriate mechanisms. Siemens advises configuring the environment according to Siemens operational guidelines in order to run the devices in a protected IT environment.
For more information on this vulnerability and more detailed mitigation instructions, please see Siemens Security Advisory SSA-275839 at the following location:
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.
No known public exploits specifically target this vulnerability.
Specially crafted PROFINET DCP broadcast packets sent to the affected products on a local Ethernet segment (Layer 2) could cause a denial-of-service condition in some services. The services may require manual restart to recover.
Duan JinTong, Ma ShaoShuai, and Cheng Lei from NSFOCUS Security Team reported this vulnerability directly to Siemens.
Critical Infrastructure Sectors: Critical Manufacturing, Food and Agriculture, Chemical, Energy, Water and Wastewater Systems
Countries/Areas Deployed: Worldwide
Company Headquarters Location: Germany