{"cve":"CVE-2021-31642","nvd":{"published":"2021-06-01T15:15:07.717","modified":"2026-06-17T03:52:06.587","status":"Modified","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-190"],"references":["http://packetstormsecurity.com/files/162934/CHIYU-IoT-Denial-Of-Service.html","https://gitbook.seguranca-informatica.pt/cve-and-exploits/cves/chiyu-iot-devices#cve-2021-31642","https://seguranca-informatica.pt/dancing-in-the-iot-chiyu-devices-vulnerable-to-remote-attacks/","https://www.chiyu-tech.com/msg/message-Firmware-update-87.html","http://packetstormsecurity.com/files/162934/CHIYU-IoT-Denial-Of-Service.html"],"products":["chiyu-tech:bf-630_firmware","chiyu-tech:bf-631_firmware","chiyu-tech:biosense_firmware","chiyu-tech:semac_d1_firmware","chiyu-tech:semac_d2_firmware","chiyu-tech:semac_d2_n300_firmware","chiyu-tech:semac_d4_firmware","chiyu-tech:semac_s1_osdp_firmware","chiyu-tech:semac_s2_firmware","chiyu-tech:semac_s3v3_firmware","chiyu-tech:webpass_firmware"],"source":"nvd","synced_at":"2026-10-19T21:18:09.669877188+00:00"},"epss":{"cve":"CVE-2021-31642","score":0.4367,"percentile":0.98742,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}