[4.2.x] Fixed CVE-2023-24580 -- Prevented DoS with too many uploaded files.

Thanks to Jakob Ackermann for the report.

tests/handlers/test_exception.py

@@ -1,6 +1,11 @@
 from django.core.handlers.wsgi import WSGIHandler
 from django.test import SimpleTestCase, override_settings
-from django.test.client import FakePayload
+from django.test.client import (
+    BOUNDARY,
+    MULTIPART_CONTENT,
+    FakePayload,
+    encode_multipart,
+)
 
 
 class ExceptionHandlerTests(SimpleTestCase):
@@ -24,3 +29,27 @@ class ExceptionHandlerTests(SimpleTestCase):
     def test_data_upload_max_number_fields_exceeded(self):
         response = WSGIHandler()(self.get_suspicious_environ(), lambda *a, **k: None)
         self.assertEqual(response.status_code, 400)
+
+    @override_settings(DATA_UPLOAD_MAX_NUMBER_FILES=2)
+    def test_data_upload_max_number_files_exceeded(self):
+        payload = FakePayload(
+            encode_multipart(
+                BOUNDARY,
+                {
+                    "a.txt": "Hello World!",
+                    "b.txt": "Hello Django!",
+                    "c.txt": "Hello Python!",
+                },
+            )
+        )
+        environ = {
+            "REQUEST_METHOD": "POST",
+            "CONTENT_TYPE": MULTIPART_CONTENT,
+            "CONTENT_LENGTH": len(payload),
+            "wsgi.input": payload,
+            "SERVER_NAME": "test",
+            "SERVER_PORT": "8000",
+        }
+
+        response = WSGIHandler()(environ, lambda *a, **k: None)
+        self.assertEqual(response.status_code, 400)