Broken Access Control in Django with Basic Auth

Broken Access Control occurs when authorization checks are missing or incorrectly enforced, allowing attackers to access resources or perform actions they should not be permitted to. In Django, combining Basic Authentication with view- or function-level permission checks can inadvertently leave authorization gaps if developers assume transport-layer security implies authorization.

Basic Auth in Django is typically implemented using django.contrib.auth.authenticate and HttpRequest.user after credentials are decoded from the Authorization header. If you use Basic Auth for authentication but do not enforce per-request permission checks (for example, relying only on whether a user is authenticated), you expose an access control weakness. An authenticated user who should have read-only access might reach admin-only endpoints if those endpoints lack explicit permission decorators or explicit user-group checks.

Consider a Django view that returns sensitive user data:

from django.http import JsonResponse
from django.contrib.auth.decorators import login_required

@login_required
def user_profile(request):
    # Vulnerable: only checks login, not role or ownership
    return JsonResponse({"username": request.user.username, "email": request.user.email})

Here, @login_required ensures a user is authenticated but does not verify role or data ownership. If the user management endpoints do not enforce object-level or role-level checks, an authenticated user who should only see their own profile could iterate over IDs and access others’ profiles (a classic BOLA/IDOR pattern). This is a Broken Access Control issue: authentication succeeded, but authorization did not.

In API contexts, especially when Basic Auth is used, it is common to skip additional authorization logic under the assumption that the client is already authenticated. Without explicit checks, views may expose list or detail endpoints to any authenticated user, violating the principle of least privilege. For example:

from rest_framework.views import APIView
from rest_framework.response import Response
from django.contrib.auth.models import User

class UserListView(APIView):
    def get(self, request):
        # Vulnerable: no per-object or role-based check
        users = User.objects.all()
        data = [{'id': u.id, 'username': u.username} for u in users]
        return Response(data)

This endpoint, even when protected by Basic Auth middleware, returns all users to any authenticated caller unless you add checks such as request.user.has_perm or scope the queryset to the requesting user. The combination of Basic Auth and missing authorization logic therefore creates a pathway for horizontal privilege escalation.

To detect such issues, scans compare runtime behavior against the OpenAPI spec and verify whether authorization checks are present for sensitive operations. They highlight endpoints where authentication is present but role-based or ownership-based checks are missing, mapping findings to OWASP API Top 10 (Broken Object Level Authorization) and compliance frameworks.

Remediation focuses on enforcing authorization after authentication. Use Django’s permission system, object-level checks, and scope-aware queries to ensure that authenticated users can only access what they are explicitly allowed to.

1) Use Django’s permission decorators or Django REST Framework’s permission classes to enforce role-based access:

from django.contrib.auth.decorators import permission_required
from django.http import JsonResponse

@permission_required("app.view_sensitive", raise_exception=True)
def sensitive_view(request):
    return JsonResponse({"message": "authorized"})

For DRF, prefer granular permissions:

from rest_framework.permissions import BasePermission, SAFE_METHODS
from rest_framework.views import APIView
from rest_framework.response import Response

class IsOwnerOrReadOnly(BasePermission):
    def has_object_permission(self, request, view, obj):
        if request.method in SAFE_METHODS:
            return True
        return obj.user == request.user

class UserDetail(APIView):
    permission_classes = [IsOwnerOrReadOnly]
    def get(self, request, pk):
        user = User.objects.get(pk=pk)
        return Response({'username': user.username})

2) Scope querysets to the requesting user to prevent horizontal access across records:

def user_profile(request):
    # Ensure users only access their own data
    profile = UserProfile.objects.get(user=request.user)
    return JsonResponse({'username': profile.user.username, 'bio': profile.bio})

3) Combine ownership checks with role checks for admin endpoints:

from django.contrib.auth.decorators import user_passes_test

def is_admin(user):
    return user.is_staff

@user_passes_test(is_admin, login_url='/login/')
def admin_panel(request):
    return JsonResponse({'admin': True})

4) When using Basic Auth in APIs, validate credentials on each request and re-check permissions rather than relying on session state:

from django.contrib.auth import authenticate
from django.http import HttpResponseForbidden

def basic_auth_view(request):
    auth = request.META.get('HTTP_AUTHORIZATION', '')
    if auth.startswith('Basic '):
        import base64
        decoded = base64.b64decode(auth.split(' ')[1]).decode('utf-8')
        username, password = decoded.split(':', 1)
        user = authenticate(request, username=username, password=password)
        if user and user.has_perm('app.access_endpoint'):
            return JsonResponse({'ok': True})
    return HttpResponseForbidden()

These patterns ensure that authentication (e.g., via Basic Auth) is followed by explicit, context-aware authorization, reducing the risk of Broken Access Control in Django-based APIs.