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Fencer Vulns
high 8.6

CVE-2021-40334 json

SSH activation problem in the proprietary management protocol (port TCP 5558)

published 2021-12-02 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27513

cvss
8.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 62%
public exploits
0
none known

Summary

Missing Handler vulnerability in the proprietary management protocol (port TCP 5558) of Hitachi Energy FOX61x, XCM20 allows an attacker that exploits the vulnerability by activating SSH on port TCP 5558 to cause disruption to the NMS and NE communication. This issue affects: Hitachi Energy FOX61x versions prior to R15A. Hitachi Energy XCM20 versions prior to R15A.

Patch / fix

  • hitachienergy fox615_firmware r15a
  • hitachienergy xcm20_firmware r15a

Vendor advisories

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

cisa ICSA-21-341-02 updated cvss 8.6

Hitachi Energy XMC20 and FOX61x

  • Hitachi Energy FOX61x < R15A Hitachi Energy XMC20 < R15A
    affected: vendor fix, mitigation “XMC20: Upgrade to Version R15A” search.abb.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

0.99% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • Hitachi Energy FOX61x
  • Hitachi Energy XCM20

Classification

Weakness

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.