CVE-2021-31643
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 88.4%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.
Description
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.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 88.45% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- 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 · chiyu-tech/semac d4 firmware · chiyu-tech/semac s3v3 firmware · chiyu-tech/semac d2 n300 firmware · chiyu-tech/semac s1 osdp firmware · chiyu-tech/webpass firmware · chiyu-tech/biosense firmware
- Source
- cve@mitre.org
EPSS 88.4% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://packetstormsecurity.com/files/162887/CHIYU-IoT-Cross-Site-Scripting.htmlExploit, Third Party Advisory, VDB Entry
- https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31643Exploit, Third Party Advisory
- https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/Exploit, Third Party Advisory
- https://www.chiyu-tech.com/msg/message-Firmware-update-87.htmlVendor Advisory
- http://packetstormsecurity.com/files/162887/CHIYU-IoT-Cross-Site-Scripting.htmlExploit, Third Party Advisory, VDB Entry
- https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31643Exploit, Third Party Advisory
- https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/Exploit, Third Party Advisory
- https://www.chiyu-tech.com/msg/message-Firmware-update-87.htmlVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.