CVE-2023-35921

Name: CVE-2023-35921
Creator: NVD / NIST
Published: 2023-07-11T10:15:10.61+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.65%

Last modified Jun 17, 2026

CVE-2023-35921 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A vulnerability has been identified in SIMATIC MV540 H (All versions < V3.3.4), SIMATIC MV540 S (All versions < V3.3.4), SIMATIC MV550 H (All versions < V3.3.4), SIMATIC MV550 S (All versions < V3.3.4), SIMATIC MV560 U (All versions < V3.3.4), SIMATIC MV560 X (All versions < V3.3.4). Affected devices cannot properly process specially crafted Ethernet frames sent to the devices. EPSS estimates a 0.65% chance of exploitation in the next 30 days.

Description

A vulnerability has been identified in SIMATIC MV540 H (All versions < V3.3.4), SIMATIC MV540 S (All versions < V3.3.4), SIMATIC MV550 H (All versions < V3.3.4), SIMATIC MV550 S (All versions < V3.3.4), SIMATIC MV560 U (All versions < V3.3.4), SIMATIC MV560 X (All versions < V3.3.4). Affected devices cannot properly process specially crafted Ethernet frames sent to the devices. This could allow an unauthenticated remote attacker to cause a denial of service condition. The affected devices must be restarted manually.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.65%

46.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Siemens	Simatic Mv540 H Firmware	< 3.3.4
Siemens	Simatic Mv540 S Firmware	< 3.3.4
Siemens	Simatic Mv550 H Firmware	< 3.3.4
Siemens	Simatic Mv550 S Firmware	< 3.3.4
Siemens	Simatic Mv560 U Firmware	< 3.3.4
Siemens	Simatic Mv560 X Firmware	< 3.3.4

References

https://cert-portal.siemens.com/productcert/pdf/ssa-561322.pdfVendor Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-561322.pdfVendor Advisory

Timeline

Published: Jul 11, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-35921?

How severe is CVE-2023-35921?

CVE-2023-35921 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.65% probability of exploitation in the next 30 days.

How do I fix CVE-2023-35921?

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-2023-35921?

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

Scan your code now

Source: NVD / NIST