CVE-2021-25666

Name: CVE-2021-25666
Creator: NVD / NIST
Published: 2021-02-09T18:15:51.573+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.69%

Last modified Jun 17, 2026

CVE-2021-25666 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. A vulnerability has been identified in SCALANCE W780 and W740 (IEEE 802.11n) family (All versions < V6.3). Sending specially crafted packets through the ARP protocol to an affected device could cause a partial denial-of-service, preventing the device to operate normally for a short period of time.. EPSS estimates a 0.69% chance of exploitation in the next 30 days.

Description

A vulnerability has been identified in SCALANCE W780 and W740 (IEEE 802.11n) family (All versions < V6.3). Sending specially crafted packets through the ARP protocol to an affected device could cause a partial denial-of-service, preventing the device to operate normally for a short period of time.

Metrics

CVSS 3.1

4.3/10

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

EPSS Probability

0.69%

48.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-770

Affected Software

Vendor	Product	Versions
Siemens	Scalance W780 Firmware	< 6.3
Siemens	Scalance W740 Firmware	< 6.3

References

https://cert-portal.siemens.com/productcert/pdf/ssa-686152.pdfVendor Advisory
https://us-cert.cisa.gov/ics/advisories/icsa-21-040-07Third Party Advisory, VDB Entry
https://cert-portal.siemens.com/productcert/pdf/ssa-686152.pdfVendor Advisory
https://us-cert.cisa.gov/ics/advisories/icsa-21-040-07Third Party Advisory, VDB Entry

Timeline

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

Frequently Asked Questions

What is CVE-2021-25666?

How severe is CVE-2021-25666?

CVE-2021-25666 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.69% probability of exploitation in the next 30 days.

How do I fix CVE-2021-25666?

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-2021-25666?

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

Scan your code now

Source: NVD / NIST