CVE-2017-9938: Siemens SIMATIC Logon

High severity, CVSS 7.5. EPSS: 2.9% chance of exploitation in the next 30 days.

A vulnerability was discovered in Siemens SIMATIC Logon (All versions before V1.6) that could allow specially crafted packets sent to the SIMATIC Logon Remote Access service on port 16389/tcp to cause a Denial-of-Service condition. The service restarts automatically.

Affected products

• Siemens SIMATIC Logon: up to and including 1.5

Published 2017-08-08. Last modified 2026-06-17.