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01 Record

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

UnratedPUBLISHEDCNA: mitre
CNA base scoreUnratedNo CNA CVSS vector

02 Description

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

03 Exploitation and scoring

Exploitation
Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
SSVC decision
Not assessed by CISA
EPSS probability
35.71% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 98.3% of scored records. A rank, not a probability.
NVD base score
9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2021-06-04 20:25Z5 YR AGO
Last updated
2024-08-03 22:55Z2 YR AGO
Reserved
2021-04-15
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-287Improper AuthenticationClass
Data version
5.1
Document digest
e5216878debb83e9484b083ac1142707b40cb491eb7e9257bbaaf12ba93f3cae

05 Affected products

VendorProductVersionsPlatforms
chiyu-techbf-430Not specified—
chiyu-techbf-430_firmwareNot specified—
chiyu-techbf-431Not specified—
chiyu-techbf-431_firmwareNot specified—
chiyu-techbf-450mNot specified—
chiyu-techbf-450m_firmwareNot specified—
chiyu-techsemac_d1Not specified—
chiyu-techsemac_d1_firmwareNot specified—
chiyu-techsemac_d2Not specified—
chiyu-techsemac_d2_firmwareNot specified—
chiyu-techsemac_d2_n300Not specified—
chiyu-techsemac_d2_n300_firmwareNot specified—
chiyu-techsemac_d4Not specified—
chiyu-techsemac_d4_firmwareNot specified—
chiyu-techsemac_s1_osdpNot specified—
chiyu-techsemac_s1_osdp_firmwareNot specified—
chiyu-techsemac_s2Not specified—
chiyu-techsemac_s2_firmwareNot specified—
chiyu-techsemac_s3v3Not specified—
chiyu-techsemac_s3v3_firmwareNot specified—

06 References