CVE-2021-27952
CVSS v3
9.8
CRITICAL
EPSS Score
1.1 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
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.
Technical details
- Published
- 2021-08-03
Frequently asked questions
What is CVE-2021-27952?
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.
Is CVE-2021-27952 actively exploited?
Active exploitation of CVE-2021-27952 has not been confirmed. Its EPSS score was 1.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-27952?
CVE-2021-27952 has a CVSS v3 base score of 9.8 (CRITICAL severity).
Is CVE-2021-27952 affecting your environment?
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