CVE-2021-31643

An XSS vulnerability exists in several IoT devices from CHIYU Technology, including SEMAC,...

5.4 Medium

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: Required

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

88.4%Up 87.3 points since Jun 2, 2021

What each source reports

NVD Score used 5.4

Record: CVE-2021-31643
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CVSS 2.0: 3.5 LowAV:N/AC:M/Au:S/C:N/I:P/A:N
Weakness: CWE-79
Updated: 2026-11-02

CVE List No score

Record: CVE-2021-31643
Updated: 2026-11-02

EUVDEUVD-2021-18531 No score

Record: EUVD-2021-18531
Updated: 2026-11-03

GitHub AdvisoriesGHSA-hxrr-8f87-qrgp No score

An XSS vulnerability exists in several IoT devices from CHIYU Technology, including SEMAC,...

Record: GHSA-hxrr-8f87-qrgp
Weakness: CWE-79
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-31643 is a medium vulnerability (CVSS 5.4) in Chiyu-tech Bf-630 Firmware, published June 1, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 88.4%, the 99th percentile. No source names a fixed version.