CVE-2021-40364

Name: CVE-2021-40364
Creator: NVD / NIST
Published: 2021-11-09T12:15:10.07+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.23%

Last modified Jun 17, 2026

CVE-2021-40364 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). The affected systems store sensitive information in log files. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

Description

A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). The affected systems store sensitive information in log files. An attacker with access to the log files could publicly expose the information or reuse it to develop further attacks on the system.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

0.23%

14.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Siemens	Simatic Pcs 7	<= 8.2
Siemens	Simatic Pcs 7	>= 9.0, < 9.1
Siemens	Simatic Pcs 7	9.1
Siemens	Simatic Wincc	<= 7.4
Siemens	Simatic Wincc	7.5
Siemens	Simatic Wincc	15
Siemens	Simatic Wincc	16
Siemens	Simatic Wincc	17

References

https://cert-portal.siemens.com/productcert/pdf/ssa-840188.pdfVendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-840188.pdfVendor Advisory

Timeline

Published: Nov 9, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40364?

How severe is CVE-2021-40364?

CVE-2021-40364 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40364?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-40364?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST