Siemens SIMATIC S7-1200 CPU PLC devices with firmware before 4.0 allow remote attackers to cause a denial of service (defect-mode transitio…

published 2014-03-22 12 y ago modified 2026-06-17 4 mo ago also EUVD-2014-2295

cvss: 7.8; version 2.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 3.7%; EPSS 3.7% chance of exploitation in 30 days, percentile 89%
public exploits: 0; none known

Siemens SIMATIC S7-1200 CPU PLC devices with firmware before 4.0 allow remote attackers to cause a denial of service (defect-mode transition) via crafted ISO-TSAP packets, a different vulnerability than CVE-2014-2257.

Vendor advisories

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

cisa ICSA-14-079-02 updated 2025-06-09 cvss 7.8

Siemens SIMATIC S7-1200 Vulnerabilities

Siemens SIMATIC S7-1200 CPU family <V4.0
affected: mitigation

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

3.68% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	2.0	7.8	AV:N/AC:L/Au:N/C:N/I:N/A:C

Classification

Weakness

CWE-399 Resource Management Errors

References

siemens.com /innovation/pool/de/forschungsfelder/siemens_security_advisory_ssa-654382.pdf
vendor-advisory
ics-cert.us-cert.gov /advisories/ICSA-14-079-02
us-government-resource
cert-portal.siemens.com /productcert/pdf/ssa-654382.pdf

Sources

CVE List CVE-2014-2256
NVD CVE-2014-2256

Fencer Intel 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