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Fencer Intel
high 8.6

CVE-2021-27662 json

KT-1 Capture-replay

published 5y ago modified 4mo ago also EUVD-2021-14408

cvss
8.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

The KT-1 door controller is susceptible to replay or man-in-the-middle attacks where an attacker can record and replay TCP packets. This issue affects Johnson Controls KT-1 all versions up to and including 3.01

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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-21-257-02 updated cvss 8.6

Johnson Controls Sensormatic Electronics KT-1

  • Sensormatic Electronics, LLC, Johnson Controls Inc. KT-1 <=3.01
    affected: fixed in 8.40, mitigation “For more detailed mitigation instructions, please see Johnson Controls Product Security Advisory JCI-PSA-2021-14” johnsoncontrols.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

0.84% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Johnson Controls KT-1

Classification

Weakness
  • CWE-294 Authentication Bypass by Capture-replay

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.