Fix incoming status creation date not being restricted to standard ISO8601 (#27655)

app/lib/activitypub/parser/status_parser.rb

@@ -53,7 +53,8 @@ class ActivityPub::Parser::StatusParser
   end
 
   def created_at
-    @object['published']&.to_datetime
+    datetime = @object['published']&.to_datetime
+    datetime if datetime.present? && (0..9999).cover?(datetime.year)
   rescue ArgumentError
     nil
   end

spec/lib/activitypub/activity/create_spec.rb

@@ -134,6 +134,46 @@ RSpec.describe ActivityPub::Activity::Create do
         subject.perform
       end
 
+      context 'when object publication date is below ISO8601 range' do
+        let(:object_json) do
+          {
+            id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+            type: 'Note',
+            content: 'Lorem ipsum',
+            published: '-0977-11-03T08:31:22Z',
+          }
+        end
+
+        it 'creates status with a valid creation date', :aggregate_failures do
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+          expect(status.text).to eq 'Lorem ipsum'
+
+          expect(status.created_at).to be_within(30).of(Time.now.utc)
+        end
+      end
+
+      context 'when object publication date is above ISO8601 range' do
+        let(:object_json) do
+          {
+            id: [ActivityPub::TagManager.instance.uri_for(sender), '#bar'].join,
+            type: 'Note',
+            content: 'Lorem ipsum',
+            published: '10000-11-03T08:31:22Z',
+          }
+        end
+
+        it 'creates status with a valid creation date', :aggregate_failures do
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+          expect(status.text).to eq 'Lorem ipsum'
+
+          expect(status.created_at).to be_within(30).of(Time.now.utc)
+        end
+      end
+
       context 'when object has been edited' do
         let(:object_json) do
           {
@@ -145,18 +185,16 @@ RSpec.describe ActivityPub::Activity::Create do
           }
         end
 
-        it 'creates status' do
+        it 'creates status with appropriate creation and edition dates', :aggregate_failures do
           status = sender.statuses.first
 
           expect(status).to_not be_nil
           expect(status.text).to eq 'Lorem ipsum'
-        end
 
-        it 'marks status as edited' do
+          expect(status.created_at).to eq '2022-01-22T15:00:00Z'.to_datetime
-          status = sender.statuses.first
 
-          expect(status).to_not be_nil
           expect(status.edited?).to be true
+          expect(status.edited_at).to eq '2022-01-22T16:00:00Z'.to_datetime
         end
       end