A vulnerability was discovered in Siemens SIMATIC Logon (All versions before V1.6) that could allow specially crafted packets sent to the S…

published 2017-08-08 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-18848

cvss: 7.5; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 2.9%; EPSS 2.9% chance of exploitation in 30 days, percentile 87%
public exploits: 0; none known

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-17-192-01 updated 2017-07-11 cvss 5.3

Siemens SIMATIC Logon

Siemens SIMATIC Logon < 1.6
affected: vendor fix siemens.de

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

2.90% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.0	7.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

n/a SIMATIC Logon All versions before V1.6

Classification

Weakness

CWE-787 Out-of-bounds Write
CWE-20 Improper Input Validation

References

siemens.com /cert/pool/cert/siemens_security_advisory_ssa-804859.pdf
vendor-advisory
securityfocus.com /bid/99539
vdb-entry, third-party-advisory
tenable.com /security/research/tra-2017-34

Sources

CVE List CVE-2017-9938
NVD CVE-2017-9938

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary