What is the CVSS score of CVE-2021-31643?

CVE-2021-31643 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 88.4%.

Is there a public PoC exploit available for CVE-2021-31643?

Yes, a public proof-of-concept exploit is available for CVE-2021-31643. Prioritise patching immediately. EPSS: 88.4%.

Bf 631 Firmware CVE-2021-31643

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2021-06-01 cve@mitre.org

XSS Bf 631 Firmware Bf 630 Firmware Semac S2 Firmware Semac D1 Firmware Semac D2 Firmware Semac D4 Firmware Semac S3V3 Firmware Semac D2 N300 Firmware Semac S1 Osdp Firmware Webpass Firmware Biosense Firmware

5.4

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

5.4 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

CVE Published

Jun 01, 2021 - 15:15 nvd

MEDIUM 5.4

DescriptionNVD

AnalysisAI

An XSS vulnerability exists in several IoT devices from CHIYU Technology, including SEMAC, Biosense, BF-630, BF-631, and Webpass due to a lack of sanitization on the component if.cgi - username. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. An XSS vulnerability exists in several IoT devices from CHIYU Technology, including SEMAC, Biosense, BF-630, BF-631, and Webpass due to a lack of sanitization on the component if.cgi - username parameter. Affected products include: Chiyu-Tech Bf-631 Firmware, Chiyu-Tech Bf-630 Firmware, Chiyu-Tech Semac S2 Firmware, Chiyu-Tech Semac D1 Firmware, Chiyu-Tech Semac D2 Firmware.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.