Fix: deny deactivated users in permission filtering and auto-login (#13623)

* Fix: Hardening sweep, ensure a user is active, not just authenticated

* Missed this test

src/paperless/auth.py

@@ -19,7 +19,10 @@ class AutoLoginMiddleware(MiddlewareMixin):
         if request.path.startswith("/api/token/") and request.method == "POST":
             return None
         try:
-            request.user = User.objects.get(username=settings.AUTO_LOGIN_USERNAME)
+            request.user = User.objects.get(
+                username=settings.AUTO_LOGIN_USERNAME,
+                is_active=True,
+            )
             auth.login(
                 request=request,
                 user=request.user,

src/paperless/tests/test_auth_middleware.py

@@ -0,0 +1,53 @@
+from django.contrib.auth.models import AnonymousUser
+from django.contrib.auth.models import User
+from django.test import RequestFactory
+from django.test import TestCase
+from django.test import override_settings
+
+from paperless.auth import AutoLoginMiddleware
+
+
+@override_settings(AUTO_LOGIN_USERNAME="autologin")
+class TestAutoLoginMiddleware(TestCase):
+    def setUp(self) -> None:
+        super().setUp()
+        self.factory = RequestFactory()
+        self.middleware = AutoLoginMiddleware(lambda request: None)
+
+    def _process(self, request):
+        # login() needs a session to write to
+        request.session = self.client.session
+        self.middleware.process_request(request)
+        return request
+
+    def test_active_user_is_logged_in(self) -> None:
+        """
+        GIVEN:
+            - AUTO_LOGIN_USERNAME names an active user
+        WHEN:
+            - A request is processed by the middleware
+        THEN:
+            - That user is attached to the request
+        """
+        user = User.objects.create_user(username="autologin")
+
+        request = self._process(self.factory.get("/"))
+
+        self.assertEqual(request.user, user)
+
+    def test_deactivated_user_is_not_logged_in(self) -> None:
+        """
+        GIVEN:
+            - AUTO_LOGIN_USERNAME names a user who has been deactivated
+        WHEN:
+            - A request is processed by the middleware
+        THEN:
+            - The request is left anonymous rather than authenticated as them
+        """
+        User.objects.create_user(username="autologin", is_active=False)
+
+        request = self.factory.get("/")
+        request.user = AnonymousUser()
+        self._process(request)
+
+        self.assertFalse(request.user.is_authenticated)