CVE-2021-31642
A denial of service condition exists after an integer overflow in several IoT devices from CHIYU Technology, including BIOSENSE, Webpass, and BF-630, BF-631, and SEMAC.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 43.7%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
A denial of service condition exists after an integer overflow in several IoT devices from CHIYU Technology, including BIOSENSE, Webpass, and BF-630, BF-631, and SEMAC. The vulnerability can be explored by sending an unexpected integer (> 32 bits) on the page parameter that will crash the web portal and making it unavailable until a reboot of the device.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 43.67% probability · 99th percentile
- Public exploits
- 1 in Exploit-DB · first 3 June 2021
- CISA KEV
- Not listed
- Weakness
- CWE-190
- Affected
- 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/bf-631 firmware · chiyu-tech/bf-630 firmware · chiyu-tech/webpass firmware · chiyu-tech/biosense firmware
- Source
- cve@mitre.org
EPSS 43.7% 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.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://packetstormsecurity.com/files/162934/CHIYU-IoT-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31642Exploit, 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/162934/CHIYU-IoT-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31642Exploit, 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.