CVE-2021-27954

8.2 highEPSS 0.9%

High (8.2) in ecobee ecobee3 lite firmware. EPSS 0.9% chance of exploitation in the next 30 days.

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.

Severity

CVSS 3.1

8.2 high

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

EPSS: 0.9% chance of exploitation in the next 30 days; higher than 60% of CVEs (scores of 2026-10-31)
CWE: CWE-787
Published: 2021-08-03
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

ecobee:ecobee3_lite_firmware

References

https://www.l9group.com/advisories/ecobee3-lite-heap-overflow
https://www.l9group.com/advisories/ecobee3-lite-heap-overflow

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