Cyber Resilience

CVE-2021-31643

MediumPublic PoC

Published: 01 June 2021

Published
01 June 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0381 88.4th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-31643 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Chiyu-Tech Bf-631 Firmware. Its CVSS base score is 5.4 (Medium).

Operationally, ranked in the top 11.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

chiyu-tech
bf-631 firmware
all versions
chiyu-tech
bf-630 firmware
all versions
chiyu-tech
semac s2 firmware
all versions
chiyu-tech
semac d1 firmware
all versions
chiyu-tech
semac d2 firmware
all versions
chiyu-tech
semac d4 firmware
all versions
chiyu-tech
semac s3v3 firmware
all versions
chiyu-tech
semac d2 n300 firmware
all versions
chiyu-tech
semac s1 osdp firmware
all versions
chiyu-tech
webpass firmware
all versions
+1 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References