Skip to content
Fencer Intel
medium 5.4

CVE-2021-31643 json

An XSS vulnerability exists in several IoT devices from CHIYU Technology, including SEMAC, Biosense, BF-630, BF-631, and Webpass due to a l…

published 5y ago modified 4mo ago also EUVD-2021-18531

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
88.5%
EPSS 88.5% chance of exploitation in 30 days, percentile 99.7%
public exploits
0
none known

Summary

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.

Is CVE-2021-31643 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

88.45% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • seguranca-informatica.pt https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/ referenced PoC, tagged "exploit" by a source, unverified
  • gitbook.seguranca-informatica.pt https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31643 referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com http://packetstormsecurity.com/files/162887/CHIYU-IoT-Cross-Site-Scripting.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.