CVE-2021-40334
SSH activation problem in the proprietary management protocol (port TCP 5558)
- Published
- Updated
- Reserved
- Assigned by
- Hitachi Energy
Description
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.
Timeline
ID reserved
By Hitachi Energy
- 3 months later
· 3 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| Hitachi EnergyCNA (assigner) | 3.1 | High8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.99% · top 37% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.6.
Weakness
Affected products
- affected R15A – < R15A
- affected R15A – < R15A
What to do
Solution: Fixed in FOX61x R15A or XMC20 R15A
Workaround: Recommended security practices and firewall configurations help protecting systems from attacks that originate from outside the network. Such practices include that network management systems and FOX61x or XMC20 networks are typically physically protected from direct access by unauthorized personnel and have no direct connections to the Internet, as well as are separated from other networks by means of a firewall system that has a minimal number of ports exposed, and others that have to be evaluated case by case. Portable computers and removable storage media should be carefully scanned for viruses before they are connected to a control system.
References (2)
- https://search.abb.com/library/Download.aspx?DocumentID=8DBD000062&LanguageCode=en&DocumentPartId=&Action=Launch (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://search.abb.com/library/Download.aspx?DocumentID=8DBD000069&LanguageCode=en&DocumentPartId=&Action=Launch (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-40334)Record last updated .