CVE-2021-31642: Chiyu-Tech Bf-630 Firmware

Medium severity, CVSS 6.5. EPSS: 43.7% chance of exploitation in the next 30 days.

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.

Affected products

• Chiyu-Tech Bf-630 Firmware: affected versions not specified
• Chiyu-Tech Bf-631 Firmware: affected versions not specified
• Chiyu-Tech Biosense Firmware: affected versions not specified
• Chiyu-Tech Semac d1 Firmware: affected versions not specified
• Chiyu-Tech Semac d2 Firmware: affected versions not specified
• Chiyu-Tech Semac d2 n300 Firmware: affected versions not specified
• Chiyu-Tech Semac d4 Firmware: affected versions not specified
• Chiyu-Tech Semac s1 Osdp Firmware: affected versions not specified
• Chiyu-Tech Semac s2 Firmware: affected versions not specified
• Chiyu-Tech Semac s3v3 Firmware: affected versions not specified
• Chiyu-Tech Webpass Firmware: affected versions not specified

Published 2021-06-01. Last modified 2026-06-17.