Fixed CVE-2019-19118 -- Required edit permissions on parent model for editable inlines in admin.

Thank you to Shen Ying for reporting this issue.

tests/admin_inlines/tests.py

@@ -1,3 +1,5 @@
+from selenium.common.exceptions import NoSuchElementException
+
 from django.contrib.admin import ModelAdmin, TabularInline
 from django.contrib.admin.helpers import InlineAdminForm
 from django.contrib.admin.tests import AdminSeleniumTestCase
@@ -862,6 +864,98 @@ class TestInlinePermissions(TestCase):
         )
 
 
+@override_settings(ROOT_URLCONF='admin_inlines.urls')
+class TestReadOnlyChangeViewInlinePermissions(TestCase):
+
+    @classmethod
+    def setUpTestData(cls):
+        cls.user = User.objects.create_user('testing', password='password', is_staff=True)
+        cls.user.user_permissions.add(
+            Permission.objects.get(codename='view_poll', content_type=ContentType.objects.get_for_model(Poll))
+        )
+        cls.user.user_permissions.add(
+            *Permission.objects.filter(
+                codename__endswith="question", content_type=ContentType.objects.get_for_model(Question)
+            ).values_list('pk', flat=True)
+        )
+
+        cls.poll = Poll.objects.create(name="Survey")
+        cls.add_url = reverse('admin:admin_inlines_poll_add')
+        cls.change_url = reverse('admin:admin_inlines_poll_change', args=(cls.poll.id,))
+
+    def setUp(self):
+        self.client.force_login(self.user)
+
+    def test_add_url_not_allowed(self):
+        response = self.client.get(self.add_url)
+        self.assertEqual(response.status_code, 403)
+
+        response = self.client.post(self.add_url, {})
+        self.assertEqual(response.status_code, 403)
+
+    def test_post_to_change_url_not_allowed(self):
+        response = self.client.post(self.change_url, {})
+        self.assertEqual(response.status_code, 403)
+
+    def test_get_to_change_url_is_allowed(self):
+        response = self.client.get(self.change_url)
+        self.assertEqual(response.status_code, 200)
+
+    def test_main_model_is_rendered_as_read_only(self):
+        response = self.client.get(self.change_url)
+        self.assertContains(
+            response,
+            '<div class="readonly">%s</div>' % self.poll.name,
+            html=True
+        )
+        input = '<input type="text" name="name" value="%s" class="vTextField" maxlength="40" required id="id_name">'
+        self.assertNotContains(
+            response,
+            input % self.poll.name,
+            html=True
+        )
+
+    def test_inlines_are_rendered_as_read_only(self):
+        question = Question.objects.create(text="How will this be rendered?", poll=self.poll)
+        response = self.client.get(self.change_url)
+        self.assertContains(
+            response,
+            '<td class="field-text"><p>%s</p></td>' % question.text,
+            html=True
+        )
+        self.assertNotContains(response, 'id="id_question_set-0-text"')
+        self.assertNotContains(response, 'id="id_related_objs-0-DELETE"')
+
+    def test_submit_line_shows_only_close_button(self):
+        response = self.client.get(self.change_url)
+        self.assertContains(
+            response,
+            '<a href="/admin/admin_inlines/poll/" class="closelink">Close</a>',
+            html=True
+        )
+        delete_link = '<p class="deletelink-box"><a href="/admin/admin_inlines/poll/%s/delete/" class="deletelink">Delete</a></p>'  # noqa
+        self.assertNotContains(
+            response,
+            delete_link % self.poll.id,
+            html=True
+        )
+        self.assertNotContains(response, '<input type="submit" value="Save and add another" name="_addanother">')
+        self.assertNotContains(response, '<input type="submit" value="Save and continue editing" name="_continue">')
+
+    def test_inline_delete_buttons_are_not_shown(self):
+        Question.objects.create(text="How will this be rendered?", poll=self.poll)
+        response = self.client.get(self.change_url)
+        self.assertNotContains(
+            response,
+            '<input type="checkbox" name="question_set-0-DELETE" id="id_question_set-0-DELETE">',
+            html=True
+        )
+
+    def test_extra_inlines_are_not_shown(self):
+        response = self.client.get(self.change_url)
+        self.assertNotContains(response, 'id="id_question_set-0-text"')
+
+
 @override_settings(ROOT_URLCONF='admin_inlines.urls')
 class SeleniumTests(AdminSeleniumTestCase):
 
@@ -1057,6 +1151,24 @@ class SeleniumTests(AdminSeleniumTestCase):
         self.assertEqual(ProfileCollection.objects.all().count(), 1)
         self.assertEqual(Profile.objects.all().count(), 3)
 
+    def test_add_inline_link_absent_for_view_only_parent_model(self):
+        user = User.objects.create_user('testing', password='password', is_staff=True)
+        user.user_permissions.add(
+            Permission.objects.get(codename='view_poll', content_type=ContentType.objects.get_for_model(Poll))
+        )
+        user.user_permissions.add(
+            *Permission.objects.filter(
+                codename__endswith="question", content_type=ContentType.objects.get_for_model(Question)
+            ).values_list('pk', flat=True)
+        )
+        self.admin_login(username='testing', password='password')
+        poll = Poll.objects.create(name="Survey")
+        change_url = reverse('admin:admin_inlines_poll_change', args=(poll.id,))
+        self.selenium.get(self.live_server_url + change_url)
+        with self.disable_implicit_wait():
+            with self.assertRaises(NoSuchElementException):
+                self.selenium.find_element_by_link_text('Add another Question')
+
     def test_delete_inlines(self):
         self.admin_login(username='super', password='secret')
         self.selenium.get(self.live_server_url + reverse('admin:admin_inlines_profilecollection_add'))