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Fencer Intel
high 8.1

CVE-2021-27395 json

A vulnerability has been identified in SIMATIC Process Historian 2013 and earlier (All versions), SIMATIC Process Historian 2014 (All versi…

published 5y ago modified 4mo ago also EUVD-2021-14150

cvss
8.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits
0
none known

Summary

A vulnerability has been identified in SIMATIC Process Historian 2013 and earlier (All versions), SIMATIC Process Historian 2014 (All versions < SP3 Update 6), SIMATIC Process Historian 2019 (All versions), SIMATIC Process Historian 2020 (All versions). An interface in the software that is used for critical functionalities lacks authentication, which could allow a malicious user to maliciously insert, modify or delete data.

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Vendor advisories

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

cisa ICSA-21-287-09 updated cvss 9.8

Siemens SIMATIC Process Historian

  • Siemens SIMATIC Process Historian 2013 and earlier
    affected: mitigation, no fix planned
  • Siemens SIMATIC Process Historian 2014 <SP3_Update_6
    affected: vendor fix, mitigation support.industry.siemens.com
  • Siemens SIMATIC Process Historian 2019
    affected: mitigation, no fix planned
  • Siemens SIMATIC Process Historian 2020
    affected: fixed in 2020, mitigation

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

Exploit prediction

0.80% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD 2.0 5.5 AV:N/AC:L/Au:S/C:N/I:P/A:P

Affected products

  • Siemens SIMATIC Process Historian 2013 and earlier
  • Siemens SIMATIC Process Historian 2014
  • Siemens SIMATIC Process Historian 2019
  • Siemens SIMATIC Process Historian 2020

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality

References

Sources

Fencer Intel 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.