CVE-2021-37172

mediumpriority · track · 30EPSS 0.009 · 60 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.92% (60th) EPSS

CVSS 5 · medium

Is it mine?

6 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · cisa_csaf_ot · nvd

EPSS · scored 2026-10-27

A vulnerability has been identified in SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (V4.5.0). Affected devices fail to authenticate against configured passwords when provisioned using TIA Portal V13. This could allow an attacker using TIA Portal V13 or later versions to bypass authentication and download arbitrary programs to the PLC. The vulnerability does not occur when TIA Portal V13 SP1 or any later version was used to provision the device.

remediations

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

A vendor fix is available.

FixedSIMATIC S7-1200 CPU family (incl. SIPLUS variants)siemens_psirt
Update to V4.5.1 or later version
https://support.industry.siemens.com/cs/ww/en/view/109793280/
FixedSIMATIC S7-1200 CPU family (incl. SIPLUS variants)cisa_csaf_ot
Update to V4.5.1 or later version
https://support.industry.siemens.com/cs/ww/en/view/109793280/
MitigationSIMATIC S7-1200 CPU family (incl. SIPLUS variants)siemens_psirt
Update to TIA Portal V13 SP1 or any later version before provisioning S7-1200 V4.5.0 devices
MitigationSIMATIC S7-1200 CPU family (incl. SIPLUS variants)cisa_csaf_ot
Update to TIA Portal V13 SP1 or any later version before provisioning S7-1200 V4.5.0 devices

cvss

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

8.1

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–8.1

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:Csecondary · CISA US

v3.18.1highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-287USCWE-287USCWE-287US

affected products (6)

Products and version ranges known to be affected.

SIMATIC S7-1200 CPU family (incl. SIPLUS variants)all versionscisa_csaf_otUS
Siemens SIMATIC S7-1200 CPU family (incl. SIPLUS variants)≤ V4.5.0cisa_csaf_otUS
Siemens SIMATIC S7-1200 CPU family (incl. SIPLUS variants)≤ V4.5.0enisa_euvdEU
siemens simatic s7-1200 cpu firmware= 4.5.0nvdUScpe:2.3:o:siemens:simatic_s7-1200_cpu_firmware:*:*:*:*:*:*:*:*
siemens simatic step 7 (tia portal)≤ 13.0nvdUScpe:2.3:a:siemens:simatic_step_7_\(tia_portal\):*:*:*:*:*:*:*:*
Siemens SIMATIC S7-1200 CPU family (incl. SIPLUS variants)≤ V4.5.0siemens_psirtDE

advisories (2)

Vendor and ecosystem advisories describing this.

SSA-830194SSA-830194: Missing Authentication Vulnerability in S7-1200 Devices2021-08-10csaf · siemens_psirtDE
SIMATIC S7-1200 PLC, version V4.5.0 fails to authenticate against configured passwords when the affected device was provisioned using TIA Portal V13. This could allow an attacker using TIA Portal V13 or later versions to bypass authentication and download arbitrary programs to the PLC. Siemens has released an update for SIMATIC S7-1200 and recommends to update to the latest version.
ICSA-21-222-09Siemens SIMATIC S7-1200 (Update A)2021-08-10icsa · cisa_csaf_otUS
SIMATIC S7-1200 PLC, version V4.5.0 fails to authenticate against configured passwords when the affected device was provisioned using TIA Portal V13. This could allow an attacker using TIA Portal V13 or later versions to bypass authentication and download arbitrary programs to the PLC. Siemens has released an update for SIMATIC S7-1200 and recommends to update to the latest version.

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 siemens_psirt NVD CVE.org MITRE

published 2021-08-10modified 2026-06-17

references (8)

External citations — patches, advisories, analysis.

scry

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