CVE-2017-13718

Starry Station (Router) HTTP API PIN Brute Force Vulnerability

• CVSS 8.0
• CWE-254
• Authentication, Authorization, and Session Management
• Remote

The HTTP API supported by Starry Station (aka Starry Router) allows brute forcing the PIN setup by the user on the device, and this allows an attacker to change the Wi-Fi settings and PIN, as well as port forward and expose any internal device's port to the Internet. It was identified that the device uses custom Python code called "rodman" that allows the mobile appication to interact with the device. The APIs that are a part of this rodman Python file allow the mobile application to interact with the device using a secret, which is a uuid4 based session identifier generated by the device the first time it is set up. However, in some cases, these APIs can also use a security code. This security code is nothing but the PIN number set by the user to interact with the device when using the touch interface on the router. This allows an attacker on the Internet to interact with the router's HTTP interface when a user navigates to the attacker's website, and brute force the credentials. Also, since the device's server sets the Access-Control-Allow-Origin header to "*", an attacker can easily interact with the JSON payload returned by the device and steal sensitive information about the device.

CVE

CVE-2017-13718

CWE

CWE-254

CVSS base score

8.0

Published

2019-06-10

OWASP

A07 Identification and Authentication Failures

Orthogonal defect classification

Function

Code defect classification

Incorrect Functionality

Category

Authentication, Authorization, and Session Management

Subcategory

Insecure Authentication Mechanisms

Accessibility scope

Remote

Impact

Unauthorized Access

Fixed by upgrading

Yes

Solution

Update Starry Station firmware to fix the vulnerability.

from flask import Flask, request, jsonify

app = Flask(__name__)

user_pins = {
    "user1": "secure_pin"
}

@app.route('/api/change_wifi_settings', methods=['POST'])
def change_wifi_settings():
    username = request.json.get('username')
    pin = request.json.get('pin')
    
    if user_pins.get(username) == pin:
        return jsonify({"success": "Wi-Fi settings changed successfully"})
    
    return jsonify({"error": "Unauthorized"}), 403

if __name__ == '__main__':
    app.run()

from flask import Flask, request, jsonify
import uuid
import hashlib

app = Flask(__name__)

user_pins = {
    "user1": hashlib.sha256("secure_pin".encode()).hexdigest()
}

def verify_pin(username, pin):
    hashed_pin = hashlib.sha256(pin.encode()).hexdigest()
    return user_pins.get(username) == hashed_pin

@app.route('/api/change_wifi_settings', methods=['POST'])
def change_wifi_settings():
    username = request.json.get('username')
    pin = request.json.get('pin')
    
    if not verify_pin(username, pin):
        return jsonify({"error": "Unauthorized"}), 403

    return jsonify({"success": "Wi-Fi settings changed successfully"})

if __name__ == '__main__':
    app.run()

@misc{vaitp:cve201713718,
  title        = {{Starry Station (Router) HTTP API PIN Brute Force Vulnerability}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2019},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2017-13718},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2017-13718/}}
}