Description
A replay attack vulnerability was discovered in a Zigbee smart home kit manufactured by Ksix (Zigbee Gateway Module = v1.0.3, Door Sensor = v1.0.7, Motion Sensor = v1.0.12), where the Zigbee anti-replay mechanism - based on the frame counter field - is improperly implemented. As a result, an attacker within wireless range can resend captured packets with a higher sequence number, which the devices incorrectly accept as legitimate messages. This allows spoofed commands to be injected without authentication, triggering false alerts and misleading the user through notifications in the mobile application used to monitor the network.
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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TheMalwareGuardian/CVE-2021-27289 ★ 1 · Apr 8, 2025
CVE-2021-27289: Playback Protection Bypass on Ksix Zigbee devices
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://www.exploit-db.com/exploits/49169
- https://www.youtube.com/watch?v=5IFUpRKEioA
- https://www.youtube.com/watch?v=XFOy3wSlC9Q
- https://www.youtube.com/watch?v=yc9IEt5IMmA
- https://packetstormsecurity.com/files/160331/Ksix-Zigbee-Devices-Playback-Protection-Bypass.html
- https://github.com/TheMalwareGuardian/CVE-2021-27289