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Here are the combined vulnerabilities in a markdown format, with duplicates removed and information merged to provide a comprehensive description for each vulnerability:

Combined Vulnerability List

This document outlines the identified vulnerabilities, detailing their descriptions, impacts, ranks, mitigations, preconditions, source code analysis, and security test cases.

1. Unprotected User Registration Endpoint

This vulnerability exposes an unprotected user registration endpoint, allowing unauthorized users to create accounts.

  • Vulnerability Name: Unprotected User Registration Endpoint

  • Description:

    • The UserViewSet in backend/users/views.py is configured as a ModelViewSet and exposed via an API endpoint. ModelViewSet automatically includes a create action, which, if not explicitly restricted, can allow unauthenticated user registration, even when default permissions are set to IsAuthenticated. An external attacker can send a POST request to the /api/users/ endpoint with user registration data. If public user registration is not intended, this endpoint allows anyone to create new user accounts without authentication.

  • Impact:

    • Unauthorized user account creation allows malicious actors to create numerous accounts, potentially leading to resource exhaustion on the server, spam or abuse of application functionalities, and potential for further attacks using created accounts.

  • Vulnerability Rank: High

  • Currently implemented mitigations:

    • Default REST_FRAMEWORK permissions are set to IsAuthenticated in backend/project_name/settings/base.py.
    • Django Defender is included for brute-force login protection, but it does not protect the registration endpoint.

  • Missing mitigations:

    • Explicitly control permissions for the create action in UserViewSet to prevent unauthorized user registration. This can be achieved by setting permissions to explicitly deny unauthenticated access to the create action or by removing the create action if public user registration is not intended.

  • Preconditions:

    • A publicly accessible instance of the Django React Boilerplate application is required to exploit this vulnerability.

  • Source code analysis:

    • backend/users/views.py: 
      from rest_framework import viewsets
from .models import User
from .serializers import UserSerializer

class UserViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer
      • UserViewSet inherits from ModelViewSet, which includes default CRUD actions, including create.
    • backend/users/routes.py: 
      from .views import UserViewSet

routes = [
    {"regex": r"users", "viewset": UserViewSet, "basename": "user"},
]
      • Registers UserViewSet to be accessible under /api/users/ endpoint.
    • backend/project_name/urls.py: 
      from rest_framework.routers import DefaultRouter
# ...
router = DefaultRouter()
routes = common_routes + users_routes # users_routes includes users endpoint
for route in routes:
    router.register(route["regex"], route["viewset"], basename=route["basename"])
urlpatterns = [
    path("api/", include(router.urls), name="api"), # API endpoints are under /api/
    # ...
]
      • Registers API routes using DefaultRouter, making UserViewSet accessible via the API.
    • backend/project_name/settings/base.py: 
      REST_FRAMEWORK = {
    # ...
    "DEFAULT_PERMISSION_CLASSES": [
        "rest_framework.permissions.IsAuthenticated",
    ],
    # ...
}
      • Sets default permission IsAuthenticated for all REST API endpoints, but this default may not prevent unauthenticated access to the create action in ModelViewSet if not explicitly overridden.
    • Vulnerability Flow:
      1. An external attacker sends a POST request to /api/users/.
      2. Django REST Framework routes the request to UserViewSet.create action.
      3. The create action, lacking explicit permission configuration, bypasses the default IsAuthenticated permission and allows unauthenticated user creation.
      4. A new user is created in the database without authentication.

  • Security test case:

    1. Deploy the Django React Boilerplate application to a publicly accessible environment.
    2. Use a tool like curl or Postman to send a POST request to /api/users/.
    3. Set the Content-Type header to application/json.
    4. Include the following JSON payload in the request body: 
      {
  "email": "[email protected]",
  "password": "P@$$wOrd123"
}
    5. Send the request without any authentication credentials.
    6. Check the HTTP response status code. A 201 Created status code indicates a successful, and thus vulnerable, user registration. A 403 Forbidden or 401 Unauthorized response indicates that the vulnerability is mitigated.
    7. If the response status code is 201 Created, verify in the Django admin panel or directly in the database if a new user with the email "[email protected]" has been created.
    8. Successful user creation without authentication confirms the vulnerability.

2. Mass Assignment / Privilege Escalation in User API

This vulnerability allows authenticated non-admin users to escalate their privileges by modifying sensitive fields in their user profile via the User API.

  • Vulnerability Name: Mass Assignment / Privilege Escalation in User API
  • Description:
    • The User API, implemented using a default DRF ModelViewSet for users, utilizes a serializer that exposes sensitive fields such as is_staff and is_superuser without marking them as read-only. An authenticated attacker (even a normal user) can send a crafted PUT or PATCH request to the user endpoint (e.g., /api/users/<user_id>/) to modify these fields and escalate their privileges to administrative levels.
  • Impact:
    • Successful exploitation allows an attacker to grant themselves or other accounts administrative privileges, leading to full system compromise, including unauthorized data access, modification, and control over backend functions.
  • Vulnerability Rank: Critical
  • Currently implemented mitigations:
    • The project uses DRF’s default IsAuthenticated permission on all API endpoints, requiring users to be signed in to access the API. However, there are no object-level access restrictions or field-level protections applied in the User serializer to prevent mass assignment.
  • Missing mitigations:
    • Mark sensitive fields (e.g., is_staff, is_superuser, is_active) as read-only in the UserSerializer or use a dedicated "update" serializer that excludes these fields.
    • Implement additional object-level permission checks in the UserViewSet to restrict updates to only the user's own account or require admin rights for modifications to other users' accounts.
  • Preconditions:
    • The attacker must be authenticated as a regular (non-admin) user.
    • The attacker needs to know or be able to enumerate user IDs or be able to target their own user ID.
  • Source code analysis:
    • backend/users/serializers.py: 
      class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = [
            "id",
            "email",
            "is_active",
            "is_staff",
            "is_superuser",
            "created",
            "modified",
            "last_login",
        ]
      • The UserSerializer includes sensitive fields without explicitly marking them as read-only, allowing update operations to modify is_staff and is_superuser.
    • backend/users/views.py: 
      class UserViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer
      • The UserViewSet does not override the update logic or queryset to restrict modifications to a user’s own record or implement permission checks to prevent privilege escalation.
  • Security test case:
    1. Log in to the application with a normal (non-admin) user account and obtain a valid session or authentication token.
    2. Identify the current user's ID (or a target user's ID) using a GET request to /api/users/.
    3. Send a PATCH request to /api/users/<user_id>/ with the following JSON payload: 
      {
  "is_superuser": true,
  "is_staff": true
}
    4. Verify that the response is 200 OK.
    5. Perform a subsequent GET request to /api/users/<user_id>/ or attempt to access admin-only functionalities to confirm that the user’s account now has elevated privileges.
    6. If the user record is updated with admin-level privileges without proper authorization, the vulnerability is confirmed.

3. Insecure ALLOWED_HOSTS Configuration

This vulnerability arises from an overly permissive ALLOWED_HOSTS setting, making the application susceptible to host header attacks.

  • Vulnerability Name: Insecure ALLOWED_HOSTS Configuration

  • Description:

    • The default ALLOWED_HOSTS setting in the render.yaml configuration file is set to '*', which signifies that the Django application will accept requests from any host. In production settings, the value for ALLOWED_HOSTS is sourced from an environment variable, and the default value is set to "*". This permissive configuration bypasses Django's built-in protection against host header attacks. An attacker can exploit this by sending requests with a forged Host header to manipulate absolute URLs (e.g., in password reset links, error emails) or facilitate host header poisoning and cache poisoning attacks.

  • Impact:

    • An insecure ALLOWED_HOSTS configuration can lead to various attacks:
      • Password reset poisoning: Attackers can initiate password reset requests and manipulate the Host header to ensure password reset links point to malicious domains.
      • Cache poisoning: If the application uses host-based caching, attackers can poison the cache with content from a malicious host.
      • Host header injection: Attackers may be able to inject malicious content by controlling the hostname used in the application's responses.
      • Redirection to malicious sites: Users can be redirected to attacker-controlled sites.
      • Session security compromise: Host header manipulation can sometimes interfere with session security.

  • Vulnerability Rank: High

  • Currently implemented mitigations:

    • Production settings use environment variables for ALLOWED_HOSTS (via config("ALLOWED_HOSTS", cast=Csv())).
    • The README.md file contains instructions to modify the ALLOWED_HOSTS setting after the initial deployment, but the default configuration is insecure.

  • Missing mitigations:

    • The default ALLOWED_HOSTS setting in render.yaml should be changed from '*' to a more secure configuration, ideally an empty list [] or a placeholder hostname like 'your-app-name.onrender.com' to encourage users to update it.
    • The environment configuration should restrict ALLOWED_HOSTS to a whitelist of known and trusted domain(s) (e.g., ["{{project_name}}-a1b2.onrender.com", "example.org"]).
    • The project bootstrap section in README.md should strongly emphasize the importance of changing the ALLOWED_HOSTS setting to the actual domain(s) of the deployed application before going to production.
    • The render_build.sh script could include a check to ensure that ALLOWED_HOSTS is not set to '*' and warn the user or fail the build if it is.

  • Preconditions:

    • The application is deployed in a publicly accessible production environment using the default render.yaml configuration.
    • The environment variable for ALLOWED_HOSTS is not properly overridden with a secure, domain-specific list.

  • Source code analysis:

    • backend/project_name/settings/production.py: 
      ALLOWED_HOSTS = config("ALLOWED_HOSTS", cast=Csv())
      • ALLOWED_HOSTS is configured to be read from the environment variable ALLOWED_HOSTS.
    • /code/render.yaml: 
      envVarGroups:
  - name: python-services
    envVars:
      - key: PYTHON_VERSION
        value: 3.12.0
      - key: POETRY_VERSION
        value: 2.0.1
      - key: SECRET_KEY
        generateValue: true
      - key: DJANGO_SETTINGS_MODULE
        value: {{project_name}}.settings.production
      - key: ALLOWED_HOSTS
        value: '*'
      • The render.yaml file sets the default value of the ALLOWED_HOSTS environment variable to '*'. This default value is used when deploying to Render.com unless overridden.
    • When ALLOWED_HOSTS is set to '*', Django disables host header validation, making the application vulnerable to host header attacks.

  • Security test case:

    1. Deploy the Django application to Render.com using the provided render.yaml file without modifying the default ALLOWED_HOSTS setting.
    2. Once deployed and accessible, use curl or browser developer tools to send a request to the application with a manipulated Host header. For example: 
      curl https://your-app-name.onrender.com -H "Host: malicious.example.com"
    3. Observe the application's response. If vulnerable, the application will respond normally despite the Host header being set to malicious.example.com.
    4. To demonstrate password reset poisoning: Initiate a password reset request for a user. Intercept the password reset email and examine the reset link. If vulnerable, the reset link will use malicious.example.com instead of the legitimate application domain, confirming the attacker's ability to control hostnames in password reset emails.