Code Review — Python 3.10 / Django 4.2 CRITICAL — Security: Missing Authentication Problem: process_payment has no authentication check. Any unauthenticated user can POST to this endpoint and trigger a charge. Fix: Add @login_required and replace the POST user_id with request.user.id: from django.contrib.auth.decorators import login_required @login_required def process_payment(request): user_id = request.user.id # Never read user identity from POST data CRITICAL — Security: User Impersonation Problem: Line 3 reads user_id from request.POST. Any logged-in user can set user_id to another user's ID and create payments attributed to them. Fix: Always use request.user.id for the current user. Remove user_id from POST entirely. CRITICAL — Security: No Input Validation on Amount Problem: amount is received as a raw string and passed directly to stripe.charge. A malicious user can send "0", "-100", or a very large number. Fix: try: amount = int(request.POST.get("amount", 0)) if amount <= 0 or amount > 999999: return JsonResponse({"error": "invalid amount"}, status=400) except ValueError: return JsonResponse({"error": "invalid amount"}, status=400) WARNING — No Error Handling for Stripe Failures Problem: If stripe.charge raises an exception — card decline, network failure — the exception propagates as a 500 error. The charge may have been initiated but Payment.objects.create was never called. Fix: try: result = stripe.charge(amount=amount, card=card_number) except stripe.error.CardError: return JsonResponse({"error": "card declined"}, status=402) except stripe.error.StripeError: return JsonResponse({"error": "payment failed"}, status=500) Summary: 3 CRITICAL, 1 WARNING. This endpoint is actively exploitable — do not deploy without fixing authentication and user impersonation first.