CVE-2021-27662: Johnsoncontrols Kantech Kt-1 Door Controller Firmware

High severity, CVSS 8.1. EPSS: 0.8% chance of exploitation in the next 30 days.

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

Affected products

• Johnsoncontrols Kantech Kt-1 Door Controller Firmware: up to and including 3.01

Published 2021-09-15. Last modified 2026-06-17.