CVE-2021-27953
CVE-2021-27953 is a high-severity vulnerability in Ecobee Ecobee3 Lite Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 7.8
- EPSS exploit prediction: 2% (74th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-476
- Affected product: Ecobee Ecobee3 Lite Firmware
- Published:
- Last modified:
Description
A NULL pointer dereference vulnerability exists on the ecobee3 lite 4.5.81.200 device in the HomeKit Wireless Access Control setup process. A threat actor can exploit this vulnerability to cause a denial of service, forcing the device to reboot via a crafted HTTP request.
Frequently asked questions
- What is CVE-2021-27953?
- A NULL pointer dereference vulnerability exists on the ecobee3 lite 4.5.81.200 device in the HomeKit Wireless Access Control setup process. A threat actor can exploit this vulnerability to cause a denial of service, forcing the device to reboot via a crafted HTTP request.
- How severe is CVE-2021-27953?
- CVE-2021-27953 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2021-27953 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-27953?
- CVE-2021-27953 affects Ecobee Ecobee3 Lite Firmware. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-27953?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-27953 published?
- CVE-2021-27953 was published on 2021-08-03 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:o:ecobee:ecobee3_lite_firmware:4.5.81.200:*:*:*:*:*:*:*
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