CVE-2016-3949

highpriority · track · 32EPSS 0.045 · 91 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

4.49% (91st) EPSS

CVSS 7.8 · high

Is it mine?

7 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cisa_csaf_ot · nvd

EPSS · scored 2026-10-27

Siemens SIMATIC S7-300 Profinet-enabled CPU devices with firmware before 3.2.12 and SIMATIC S7-300 Profinet-disabled CPU devices with firmware before 3.3.12 allow remote attackers to cause a denial of service (defect-mode transition) via crafted (1) ISO-TSAP or (2) Profibus packets.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

No vendor fix yet; a mitigation is available.

MitigationSIMATIC S7-300 CPUs with Profinet supportcisa_csaf_ot
Siemens has released SIMATIC S7-300 firmware Versions V3.2.12 and V3.3.12, which fix the vulnerability, and recommends users update to the latest version. Users can find this firmware at the following location: https://support.industry.siemens.com/cs/ww/en/ps/13752)
MitigationSIMATIC S7-300 CPUs without Profinet supportcisa_csaf_ot
Siemens has released SIMATIC S7-300 firmware Versions V3.2.12 and V3.3.12, which fix the vulnerability, and recommends users update to the latest version. Users can find this firmware at the following location: https://support.industry.siemens.com/cs/ww/en/ps/13752)

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.8

v2.07.8highAV:N/AC:L/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 10 · impact 6.9

v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · CISA US

v3.06.9mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-399USprimaryCWE-664US

affected products (7)

Products and version ranges known to be affected.

Siemens SIMATIC S7-300 CPUs with Profinet support: <=3.2.12all versionscisa_csaf_otUS
Siemens SIMATIC S7-300 CPUs without Profinet support: <=3.3.12all versionscisa_csaf_otUS
Siemens SIMATIC S7-300 CPUs with Profinet support≤ 3.2.12cisa_csaf_otUS
Siemens SIMATIC S7-300 CPUs without Profinet support≤ 3.3.12cisa_csaf_otUS
n/a n/a≤ n/aenisa_euvdEU
siemens simatic s7-300 with profitnet support firmware= 3.2.11nvdUScpe:2.3:o:siemens:simatic_s7-300_with_profitnet_support_firmware:*:*:*:*:*:*:*:*
siemens simatic s7-300 without profitnet support firmware= 3.3.11nvdUScpe:2.3:o:siemens:simatic_s7-300_without_profitnet_support_firmware:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

ICSA-16-161-01Siemens SIMATIC S7-300 Denial-of-Service Vulnerability2016-03-13icsa · cisa_csaf_otUS
This CSAF advisory was extracted from unstructured data and may contain inaccuracies. If you notice any errors, please reach out to the designated contact at CISA CSAF: central@cisa.dhs.gov

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cisa_csaf_ot nvd NVD CVE.org MITRE

published 2016-06-27modified 2026-06-17

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+3721 more

references (12)

External citations — patches, advisories, analysis.

scry

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