Cyber Resilience

CVE-2021-27662

High

Published: 15 September 2021

Published
15 September 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
EPSS Score 0.0018 39.5th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-27662 is a high-severity Authentication Bypass by Capture-replay (CWE-294) vulnerability in Johnsoncontrols Kantech Kt-1 Door Controller Firmware. Its CVSS base score is 8.6 (High).

Operationally, ranked at the 39.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

johnsoncontrols
kantech kt-1 door controller firmware
≤ 3.01

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-294

Allows detection of capture-replay attacks by showing the replayed logon's timestamp as the last logon.

addresses: CWE-294

Protects against replay of captured session tokens or credentials by requiring authenticated, fresh session channels.

addresses: CWE-294

Wireless link protections commonly incorporate replay protection, reducing the exploitability of capture-replay weaknesses.

addresses: CWE-294

Accurate synchronized time enables tight timestamp windows that directly limit capture-replay windows in authentication protocols.

References