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Fencer Vulns
medium 4.3

CVE-2021-25666 json

A vulnerability has been identified in SCALANCE W780 and W740 (IEEE 802.11n) family (All versions < V6.3).

published 2021-02-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-12558

cvss
4.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

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.

Patch / fix

  • siemens scalance_w780_firmware 6.3
  • siemens scalance_w740_firmware 6.3

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-040-07 updated cvss 4.3

Siemens SCALANCE W780 and W740

  • Siemens SCALANCE W780 and W740 (IEEE 802.11n) family <V6.3
    affected: fixed in V6.3

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.3 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 2.0 3.3 AV:A/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • Siemens SCALANCE W780 and W740 (IEEE 802.11n) family

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.