Security readout for executives and security teams
Plain-English summary
CVE-2021-27952 describes hardcoded default root credentials on ecobee3 lite 4.5.81.200. The reported path requires access to the device serial console, so this is primarily a physical or hardware-access risk, not evidence of broad internet exploitation.
Executive priority
Prioritize this for environments where thermostat hardware is publicly accessible or located in semi-trusted spaces. For tightly controlled facilities, handle through normal IoT risk management and vendor update tracking.
Technical view
The CVE states that default root credentials allow access to the password-protected bootloader environment through the serial console on ecobee3 lite 4.5.81.200. Public metadata provides no CVSS score, CWE mapping, CPE, confirmed patch, or named mitigation in the supplied sources.
Likely exposure
Organizations are most exposed where ecobee3 lite devices are deployed in locations accessible to visitors, contractors, tenants, or untrusted staff. Exposure is lower for devices in controlled areas. The supplied sources do not establish remote network exploitability.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. Exploitation requires serial console access according to the CVE description, implying physical device access or equivalent hardware-level access.
Researcher notes
Evidence is limited to the CVE description and referenced advisory. The record names serial-console bootloader access via hardcoded root credentials but does not provide CVSS, a patch statement, exploitation evidence, or affected CPE data.
Mitigation direction
- Check ecobee or vendor guidance for firmware updates or official mitigation advice.
- Restrict physical access to installed ecobee3 lite devices.
- Include these devices in asset inventory and facilities security reviews.
- Treat untrusted or tampered devices as requiring replacement or vendor assessment.
Validation and detection
- Identify whether ecobee3 lite devices are present in managed facilities.
- Confirm firmware or device version against 4.5.81.200 records.
- Review whether deployed units are physically accessible to untrusted people.
- Check vendor support channels for current remediation guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
Credential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-27952 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.l9group.com/advisories/hard-coded-default-root-credentials-for-all-ecobee3-lite-devicesCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.