ICSA-18-079-02: Siemens SIMATIC, SINUMERIK, and PROFINET IO (Update D)

CISA's summary

Summary: Several industrial controllers are affected by a security vulnerability that could allow an attacker to cause a denial of service condition via PROFINET DCP network packets under certain circumstances. Precondition for this scenario is a direct OSI Layer 2 access to the affected products. PROFIBUS interfaces are not affected. Siemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where updates are not, or not yet available.

Products, as the advisory lists them

DeSpy has not checked any unit, hardware revision or firmware.

Vulnerabilities in this advisory

• CVE-2018-4843 — CVE-2018-4843 · CWE-20

  Responding to a PROFINET DCP request with a specially crafted PROFINET DCP packet could cause a denial of service condition of the requesting system. The security vulnerability could be exploited by an attacker located on the same Ethernet segment (OSI Layer 2) as the targeted device. A manual restart is required to recover the system.

Acknowledgments, as the advisory lists them

• Siemens ProductCERT: reporting this vulnerability to CISA.

The advisory's legal notice

Siemens Security Advisories are subject to the terms and conditions contained in Siemens' underlying license terms or other applicable agreements previously agreed to with Siemens (hereinafter "License Terms"). To the extent applicable to information, software or documentation made available in or through a Siemens Security Advisory, the Terms of Use of Siemens' Global Website (https://www.siemens.com/terms_of_use, hereinafter "Terms of Use"), in particular Sections 8-10 of the Terms of Use, shall apply additionally. In case of conflicts, the License Terms shall prevail over the Terms of Use.

Sources

• The advisory at cisa.gov
• The CSAF document (JSON)

DeSpy's copy of this version is dated 2026-09-28.