CVE-2024-27081 is a high-severity (CVSS 7.2) Path Traversal vulnerability in esphome. A fix is available for esphome — see the affected versions and patch details below.
ESPHome remote code execution via arbitrary file write
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-27081.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
esphomeReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Security misconfiguration in edit configuration file API in dashboard component of ESPHome version 2023.12.9 (command line installation) allows authenticated remote attackers to read and write arbitrary files under the configuration directory rendering remote code execution possible.
Details
It is possible to abuse this path traversal vulnerability both in command line installation and Home Assistant add-on, but it is possible to read and write files only under the configuration directory.
The vulnerability is present and exploitable in the command line installation, but it was not possible to confirm an impact in the home assistant add-on version.
PoC
<img width="482" alt="/edit?configuration=/config/.esphome/esphome.json" src="https://github.com/esphome/esphome/assets/115887876/d2da3180-976e-4bed-b4b9-35ac960a7fb4"> <br/> <img width="344" alt="/edit?configuration=/config/.esphome/build/test01/src/main.cpp (firmware for board named test01)" src="https://github.com/esphome/esphome/assets/115887876/707fb6d7-d4a8-461e-bbb7-05382471e925"> <br/> <img width="482" alt="RCE payload POST request on /edit?configuration=.esphome/platformio/packages/tool-esptoolpy/esptool.py" src="https://github.com/esphome/esphome/assets/115887876/c6cb28d8-352d-4fea-b77a-705f63be94e3"> <br/> <img width="482" alt="Arbitrary code execution during ESP board flashing" src="https://github.com/esphome/esphome/assets/115887876/5eb0f14c-ceb2-4b15-8898-c02c610763d1">Impact
The issue gives read and write access to files under the configuration directory and allows malicious users to write arbitrary code in python scripts executed during the compilation and flashing of firmwares for ESP boards.
If chained with GHSA-9p43-hj5j-96h5 and GHSA-5925-88xh-6h99, this issue could allow an unauthenticated remote user to gain remote code execution on the machine hosting the dashboard.
It also allows accessing sensitive information such as esphome.json and board firmware source code allowing a user to modify the board firmware, and leaking secrets such as: WiFi network credentials, fallback hotspot WiFi credentials, OTA component authentication password and API encryption key.
Credits
Spike Reply Cybersecurity Team
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | esphome | ≥ 2023.12.9&&< 2024.2.1 | 2024.2.1pip install --upgrade 'esphome==2024.2.1' |
Affected Products
esphomeesphomeDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for esphome, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update esphome to 2024.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27081 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2024-27081 in your dependencies?
Find it across PyPI, including transitive dependencies.