CVE-2021-31251

An authentication bypass in telnet server in BF-430 and BF431 232/422 TCP/IP Converter, BF-450M and SEMAC from CHIYU Technology Inc allows obtaining a privileged connection with the target device by supplying a specially malformed request and an attacker may force the remote telnet server to believe that the user has already authenticated.

CVSS v3.1 NVD

9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v2.0 NVD

7.5 HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P

EPSS

35.71% chance of exploitation in the next 30 days, 98th percentile

Published

2021-06-04

Updated

2024-08-03

Proof-of-concept exploits (1)

• https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021…

ExploitDB entries (1)

• https://www.exploit-db.com/exploits/49936

Security advisories

• https://www.chiyu-tech.com/msg/message-Firmware-update-87.html
• https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-at…

References

• CVE Record
• NVD entry