CVE-2021-41104
7.5 · HIGHOverview
CVE-2021-41104 is a high-severity vulnerability affecting esphome esphome_firmware. It was published on September 28, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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`.
Remediation
Check the references section for vendor advisories and patches from esphome. Update esphome_firmware to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| esphome | esphome_firmware | >= 0, < 2021.9.2 | Affected |
References
Frequently Asked Questions
What is CVE-2021-41104?
CVE-2021-41104 is a high-severity vulnerability affecting esphome esphome_firmware. It was published on September 28, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2021-41104?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-41104?
Check the references section for vendor advisories and patches from esphome. Update esphome_firmware to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-41104?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-41104 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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