CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVE-2021-31251
Critical (9.8) in chiyu-tech. EPSS 36% chance of exploitation in the next 30 days.
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.
Severity
- EPSS
- 36% chance of exploitation in the next 30 days; higher than 98% of CVEs (scores of 2026-10-31)
- CWE
- CWE-287
- Published
- Modified
- Record from
- the NVD, synced
Affected
- chiyu-tech:bf-430_firmware
- chiyu-tech:bf-431_firmware
- chiyu-tech:bf-450m_firmware
- chiyu-tech:semac_d1_firmware
- chiyu-tech:semac_d2_firmware
- chiyu-tech:semac_d2_n300_firmware
- chiyu-tech:semac_d4_firmware
- chiyu-tech:semac_s1_osdp_firmware
- chiyu-tech:semac_s2_firmware
- chiyu-tech:semac_s3v3_firmware
References
- https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31251
- https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/#.YLqK1KhKguU
- https://www.chiyu-tech.com/msg/message-Firmware-update-87.html
- https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31251
- https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/#.YLqK1KhKguU