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Fencer Intel
high 8.2

CVE-2021-27954 json

A heap-based buffer overflow vulnerability exists on the ecobee3 lite 4.5.81.200 device in the HKProcessConfig function of the HomeKit Wire…

published 5y ago modified 4mo ago also EUVD-2021-14672

cvss
8.2
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

A heap-based buffer overflow vulnerability exists on the ecobee3 lite 4.5.81.200 device in the HKProcessConfig function of the HomeKit Wireless Access Control setup process. A threat actor can exploit this vulnerability to force the device to connect to a SSID or cause a denial of service.

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Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • l9group.com https://www.l9group.com/advisories/ecobee3-lite-heap-overflow referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:N/I:P/A:P

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.