CVE-2021-31251 (bf-430_firmware, bf-431_firmware, bf-450m_firmware, semac_d1_firmware, semac_d2_firmware, semac_d2_n300_firmware, semac_d4_firmware, semac_s1_osdp_firmware, semac_s2_firmware, semac_s3v3_firmware)

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.