CVE-2021-31642

A denial of service condition exists after an integer overflow in several IoT devices from CHIYU...

6.5 MediumPublic exploit

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

43.7%Up 42.6 points since Jun 2, 2021

What each source reports

NVD Score used 6.5

Record: CVE-2021-31642
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 6.8 MediumAV:N/AC:L/Au:S/C:N/I:N/A:C
Weakness: CWE-190
Updated: 2026-11-02

CVE List No score

Record: CVE-2021-31642
Updated: 2026-11-02

EUVDEUVD-2021-18530 No score

Record: EUVD-2021-18530
Updated: 2026-11-03

GitHub AdvisoriesGHSA-6jfx-f65x-7qfx No score

A denial of service condition exists after an integer overflow in several IoT devices from CHIYU...

Record: GHSA-6jfx-f65x-7qfx
Weakness: CWE-190
Updated: 2026-11-02

Affected products

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
Exploit-DB	CHIYU IoT Devices - Denial of Service (DoS)	2021-06-03

History

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

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

In short

CVE-2021-31642 is a medium vulnerability (CVSS 6.5) in Chiyu-tech Bf-630 Firmware, published June 1, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 43.7%, the 98th percentile. No source names a fixed version.