CVE-2021-27952
Hardcoded default root credentials exist on the ecobee3 lite 4.5.81.200 device. This allows a...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-27952- 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 - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-798
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-27952- Updated
- 2026-11-02
EUVDEUVD-2021-14670 No score
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.
- Record
EUVD-2021-14670- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3xpf-gg8x-9h3c No score
Hardcoded default root credentials exist on the ecobee3 lite 4.5.81.200 device. This allows a...
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.
- Record
GHSA-3xpf-gg8x-9h3c- Weakness
- CWE-798
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-27952 is a critical vulnerability (CVSS 9.8) in Ecobee Ecobee3 Lite Firmware, published August 3, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.13%, the 66th percentile. No source names a fixed version.