{"cve":"CVE-2021-41104","nvd":{"published":"2021-09-28T16:15:08.413","modified":"2026-06-17T04:07:52.940","status":"Modified","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-306"],"references":["https://github.com/esphome/esphome/pull/2409/commits/207cde1667d8c799a197b78ca8a5a14de8d5ca1e","https://github.com/esphome/esphome/releases/tag/2021.9.2","https://github.com/esphome/esphome/security/advisories/GHSA-48mj-p7x2-5jfm","https://github.com/esphome/esphome/pull/2409/commits/207cde1667d8c799a197b78ca8a5a14de8d5ca1e","https://github.com/esphome/esphome/releases/tag/2021.9.2"],"products":["esphome:esphome_firmware"],"source":"nvd","synced_at":"2026-10-19T21:23:41.316049955+00:00"},"epss":{"cve":"CVE-2021-41104","score":0.01213,"percentile":0.68531,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-48mj-p7x2-5jfm","url":"https://osv.dev/vulnerability/GHSA-48mj-p7x2-5jfm","summary":"Basic auth bypass in esphome","modified":"2026-05-04T08:45:54.767868579Z","packages":[{"ecosystem":"PyPI","name":"esphome","purl":"pkg:pypi/esphome","ranges":["<2021.9.2"],"fixed":["2021.9.2"]}]},{"id":"PYSEC-2021-351","url":"https://osv.dev/vulnerability/PYSEC-2021-351","summary":"","modified":"2023-11-08T04:06:51.299405Z","packages":[{"ecosystem":"PyPI","name":"esphome","purl":"pkg:pypi/esphome","ranges":["<2021.9.2"],"fixed":["2021.9.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}