What is the CVSS score of CVE-2021-31251?

CVE-2021-31251 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 35.7%.

Is there a public PoC exploit available for CVE-2021-31251?

Yes, a public proof-of-concept exploit is available for CVE-2021-31251. Prioritise patching immediately. EPSS: 35.7%.

Bf 430 Firmware CVE-2021-31251

CRITICAL

Improper Authentication (CWE-287)

2021-06-04 cve@mitre.org

Authentication Bypass Bf 430 Firmware Bf 431 Firmware Bf 450M Firmware Semac S2 Firmware Semac D1 Firmware Semac D2 Firmware Semac D4 Firmware Semac S3V3 Firmware Semac D2 N300 Firmware Semac S1 Osdp Firmware

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Jun 04, 2021 - 21:15 nvd

CRITICAL 9.8

DescriptionNVD

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.

AnalysisAI

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. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Improper Authentication (CWE-287), which allows attackers to bypass authentication mechanisms to gain unauthorized access. 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. Affected products include: Chiyu-Tech Bf-430 Firmware, Chiyu-Tech Bf-431 Firmware, Chiyu-Tech Bf-450M Firmware, Chiyu-Tech Semac S2 Firmware, Chiyu-Tech Semac D1 Firmware.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Implement multi-factor authentication, enforce strong password policies, use proven authentication frameworks.