CVE-2021-27952

9.8 criticalEPSS 1.1%

Critical (9.8) in ecobee ecobee3 lite firmware. EPSS 1.1% chance of exploitation in the next 30 days.

Hardcoded default root credentials exist on the ecobee3 lite 4.5.81.200 device. This allows a threat actor to gain access to the password-protected bootloader environment through the serial console.

Severity

CVSS 3.1

9.8 critical

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

EPSS: 1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-31)
CWE: CWE-798
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/hard-coded-default-root-credentials-for-all-ecobee3-lite-devices
https://www.l9group.com/advisories/hard-coded-default-root-credentials-for-all-ecobee3-lite-devices

Check your stack JSON