CVE-2021-31251 in the critical feed json
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…
published 5y ago modified 4mo ago also EUVD-2021-18163
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 35.7%
- EPSS 35.7% chance of exploitation in 30 days, percentile 98%
- public exploits
- 1
- Exploit-DB
Summary
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.
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- First public exploit (EDB-49936)
- Published
Exploit prediction
35.71% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- EDB-49936 CHIYU IoT Devices - 'Telnet' Authentication Bypass remote, 2021-06-03
- gitbook.seguranca-informatica.pt https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31251 referenced PoC, tagged "exploit" by a source, unverified
- seguranca-informatica.pt https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/#.YLqK1KhKguU referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
gitbook.seguranca-informatica.pt
/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31251
exploit, third-party-advisory
-
seguranca-informatica.pt
/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/#.YLqK1KhKguU
exploit, third-party-advisory
-
chiyu-tech.com
/msg/message-Firmware-update-87.html
vendor-advisory
Sources
- CVE List CVE-2021-31251
- NVD CVE-2021-31251
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