CVE-2021-41104

HIGH
Published Sep 28, 20214y ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Sep 28, 2021 4y ago
Last Modified Jun 17, 2026 2w ago

Description

ESPHome is a system to control the ESP8266/ESP32. Anyone with web_server enabled and HTTP basic auth configured on version 2021.9.1 or older is vulnerable to an issue in which `web_server` allows over-the-air (OTA) updates without checking user defined basic auth username & password. This issue is patched in version 2021.9.2. As a workaround, one may disable or remove `web_server`.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity High
Availability None

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-306 Missing Authentication for Critical Function Authentication

Affected Products 3

VendorProductVersionRange
esphomeesphome_firmware* <2021.9.2
espressifesp32*any
espressifesp8266*any

References 3

  • github.com https://github.com/esphome/esphome/pull/2409/commits/207cde1667d8c799a197b78ca8a5a14de8d5ca1e
    PatchThird Party Advisory
  • github.com https://github.com/esphome/esphome/releases/tag/2021.9.2
    Release NotesThird Party Advisory
  • github.com https://github.com/esphome/esphome/security/advisories/GHSA-48mj-p7x2-5jfm
    PatchThird Party Advisory

Remediation

  • github.com https://github.com/esphome/esphome/pull/2409/commits/207cde1667d8c799a197b78ca8a5a14de8d5ca1e
    PatchThird Party Advisory
  • github.com https://github.com/esphome/esphome/security/advisories/GHSA-48mj-p7x2-5jfm
    PatchThird Party Advisory