{"cve":"CVE-2021-27954","nvd":{"published":"2021-08-03T15:15:08.343","modified":"2026-06-17T03:45:40.283","status":"Modified","description":"A heap-based buffer overflow vulnerability exists on the ecobee3 lite 4.5.81.200 device in the HKProcessConfig function of the HomeKit Wireless Access Control setup process. A threat actor can exploit this vulnerability to force the device to connect to a SSID or cause a denial of service.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","score":8.2},"cwes":["CWE-787"],"references":["https://www.l9group.com/advisories/ecobee3-lite-heap-overflow","https://www.l9group.com/advisories/ecobee3-lite-heap-overflow"],"products":["ecobee:ecobee3_lite_firmware"],"source":"nvd","synced_at":"2026-10-19T21:21:13.713336758+00:00"},"epss":{"cve":"CVE-2021-27954","score":0.00936,"percentile":0.60803,"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."]}