Auth bypass in Chiyu-tech Bf-430

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…

Vulnerability class: Broken Authentication

EPSS: 0.357 (98.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-31251?
CVE-2021-31251 is a critical-severity vulnerability in Chiyu-tech Bf-430, classified under Improper Authentication. CVSS score: 9.8/10. Published 2021-06-04.
How severe is CVE-2021-31251?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-31251 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.