CVE-2023-26150 (Python, published 2023-10-03T05:15Z)
Description: value: Versions of the package asyncua before 0.9.96 are vulnerable to Improper Authentication such that it is possible to access Address Space without encryption and authentication.**Note:**This issue is a result of missing checks for services that require an active session.
Severity: nan (CVSS v3 base score: 7.5)
Weakness: CWE-287 \u2014 Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
Repository: https://github.com/FreeOpcUa/opcua-asyncio
Files changed:
asyncua/server/internal_session.py
asyncua/server/uaprocessor.py
Commit message: check if session is active


Vulnerable code:

        elif typeid == ua.NodeId(ua.ObjectIds.ReadRequest_Encoding_DefaultBinary):
            _logger.info("Read request (%s)", user)
            params = struct_from_binary(ua.ReadParameters, body)
            results = await self.session.read(params)
            response = ua.ReadResponse()
            response.Results = results
            # _logger.info("sending read response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.WriteRequest_Encoding_DefaultBinary):
            _logger.info("Write request (%s)", user)
            params = struct_from_binary(ua.WriteParameters, body)
            results = await self.session.write(params)
            response = ua.WriteResponse()
            response.Results = results
            # _logger.info("sending write response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.BrowseRequest_Encoding_DefaultBinary):
            _logger.info("Browse request (%s)", user)
            params = struct_from_binary(ua.BrowseParameters, body)
            results = await self.session.browse(params)
            response = ua.BrowseResponse()
            response.Results = results
            # _logger.info("sending browse response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)


        elif typeid == ua.NodeId(ua.ObjectIds.TranslateBrowsePathsToNodeIdsRequest_Encoding_DefaultBinary):
            _logger.info("translate browsepaths to nodeids request (%s)", user)
            params = struct_from_binary(ua.TranslateBrowsePathsToNodeIdsParameters, body)
            paths = await self.session.translate_browsepaths_to_nodeids(params.BrowsePaths)
            response = ua.TranslateBrowsePathsToNodeIdsResponse()
            response.Results = paths
            # _logger.info("sending translate browsepaths to nodeids response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.AddNodesRequest_Encoding_DefaultBinary):
            _logger.info("add nodes request (%s)", user)
            params = struct_from_binary(ua.AddNodesParameters, body)
            results = await self.session.add_nodes(params.NodesToAdd)
            response = ua.AddNodesResponse()
            response.Results = results
            # _logger.info("sending add node response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.DeleteNodesRequest_Encoding_DefaultBinary):
            _logger.info("delete nodes request (%s)", user)
            params = struct_from_binary(ua.DeleteNodesParameters, body)
            results = await self.session.delete_nodes(params)
            response = ua.DeleteNodesResponse()
            response.Results = results
            # _logger.info("sending delete node response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.AddReferencesRequest_Encoding_DefaultBinary):
            _logger.info("add references request (%s)", user)
            params = struct_from_binary(ua.AddReferencesParameters, body)
            results = await self.session.add_references(params.ReferencesToAdd)
            response = ua.AddReferencesResponse()
            response.Results = results
            # _logger.info("sending add references response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.DeleteReferencesRequest_Encoding_DefaultBinary):
            _logger.info("delete references request (%s)", user)
            params = struct_from_binary(ua.DeleteReferencesParameters, body)
            results = await self.session.delete_references(params.ReferencesToDelete)
            response = ua.DeleteReferencesResponse()
            response.Parameters.Results = results
            # _logger.info("sending delete references response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.CreateSubscriptionRequest_Encoding_DefaultBinary):
            _logger.info("create subscription request (%s)", user)
            params = struct_from_binary(ua.CreateSubscriptionParameters, body)
            result = await self.session.create_subscription(params, callback=self.forward_publish_response)
            response = ua.CreateSubscriptionResponse()
            response.Parameters = result
            # _logger.info("sending create subscription response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.ModifySubscriptionRequest_Encoding_DefaultBinary):
            _logger.info("modify subscription request")
            params = struct_from_binary(ua.ModifySubscriptionParameters, body)

            result = self.session.modify_subscription(params, self.forward_publish_response)

            response = ua.ModifySubscriptionResponse()
            response.Parameters = result

            #_logger.info("sending modify subscription response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.DeleteSubscriptionsRequest_Encoding_DefaultBinary):
            _logger.info("delete subscriptions request (%s)", user)
            params = struct_from_binary(ua.DeleteSubscriptionsParameters, body)
            results = await self.session.delete_subscriptions(params.SubscriptionIds)
            response = ua.DeleteSubscriptionsResponse()
            response.Results = results
            # _logger.info("sending delete subscription response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.CreateMonitoredItemsRequest_Encoding_DefaultBinary):
            _logger.info("create monitored items request (%s)", user)
            params = struct_from_binary(ua.CreateMonitoredItemsParameters, body)
            results = await self.session.create_monitored_items(params)
            response = ua.CreateMonitoredItemsResponse()
            response.Results = results
            # _logger.info("sending create monitored items response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.ModifyMonitoredItemsRequest_Encoding_DefaultBinary):
            _logger.info("modify monitored items request (%s)", user)
            params = struct_from_binary(ua.ModifyMonitoredItemsParameters, body)
            results = await self.session.modify_monitored_items(params)
            response = ua.ModifyMonitoredItemsResponse()
            response.Results = results
            # _logger.info("sending modify monitored items response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.DeleteMonitoredItemsRequest_Encoding_DefaultBinary):
            _logger.info("delete monitored items request (%s)", user)
            params = struct_from_binary(ua.DeleteMonitoredItemsParameters, body)
            results = await self.session.delete_monitored_items(params)
            response = ua.DeleteMonitoredItemsResponse()
            response.Results = results
            # _logger.info("sending delete monitored items response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.HistoryReadRequest_Encoding_DefaultBinary):
            _logger.info("history read request (%s)", user)
            params = struct_from_binary(ua.HistoryReadParameters, body)
            results = await self.session.history_read(params)
            response = ua.HistoryReadResponse()
            response.Results = results
            # _logger.info("sending history read response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.RegisterNodesRequest_Encoding_DefaultBinary):
            _logger.info("register nodes request (%s)", user)
            params = struct_from_binary(ua.RegisterNodesParameters, body)
            _logger.info("Node registration not implemented")
            response = ua.RegisterNodesResponse()
            response.Parameters.RegisteredNodeIds = params.NodesToRegister
            # _logger.info("sending register nodes response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.UnregisterNodesRequest_Encoding_DefaultBinary):
            _logger.info("unregister nodes request (%s)", user)
            params = struct_from_binary(ua.UnregisterNodesParameters, body)
            response = ua.UnregisterNodesResponse()
            # _logger.info("sending unregister nodes response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.PublishRequest_Encoding_DefaultBinary):
            _logger.debug("publish request (%s)", user)
            if not self.session:
                return False
            params = struct_from_binary(ua.PublishParameters, body)
            data = PublishRequestData(requesthdr=requesthdr, seqhdr=seqhdr)
            # Store the Publish Request (will be used to send publish answers from server)
            self._publish_requests.append(data)
            # If there is an enqueued result forward it immediately
            while self._publish_results:
                result = self._publish_results.popleft()
                if result.SubscriptionId not in self.session.subscription_service.active_subscription_ids:
                    # Discard the result if the subscription is no longer active
                    continue
                await self.forward_publish_response(result)
                break
            self.session.publish(params.SubscriptionAcknowledgements)
            # _logger.debug("publish forward to server")

        elif typeid == ua.NodeId(ua.ObjectIds.RepublishRequest_Encoding_DefaultBinary):
            _logger.info("re-publish request (%s)", user)
            params = struct_from_binary(ua.RepublishParameters, body)
            msg = self.session.republish(params)
            response = ua.RepublishResponse()
            response.NotificationMessage = msg
            self.send_response(requesthdr.RequestHandle, seqhdr, response)


        elif typeid == ua.NodeId(ua.ObjectIds.CallRequest_Encoding_DefaultBinary):
            _logger.info("call request (%s)", user)
            params = struct_from_binary(ua.CallParameters, body)
            results = await self.session.call(params.MethodsToCall)
            response = ua.CallResponse()
            response.Results = results
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.SetMonitoringModeRequest_Encoding_DefaultBinary):
            _logger.info("set monitoring mode request (%s)", user)
            params = struct_from_binary(ua.SetMonitoringModeParameters, body)
            # FIXME: Implement SetMonitoringMode
            # For now send dummy results to keep clients happy
            response = ua.SetMonitoringModeResponse()
            results = ua.SetMonitoringModeResult()
            ids = params.MonitoredItemIds
            statuses = [ua.StatusCode(ua.StatusCodes.Good) for node_id in ids]
            results.Results = statuses
            response.Parameters = results
            _logger.info("sending set monitoring mode response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

        elif typeid == ua.NodeId(ua.ObjectIds.SetPublishingModeRequest_Encoding_DefaultBinary):
            _logger.info("set publishing mode request (%s)", user)
            params = struct_from_binary(ua.SetPublishingModeParameters, body)
            # FIXME: Implement SetPublishingMode
            # For now send dummy results to keep clients happy
            response = ua.SetPublishingModeResponse()
            results = ua.SetPublishingModeResult()
            ids = params.SubscriptionIds
            statuses = [ua.StatusCode(ua.StatusCodes.Good) for node_id in ids]
            results.Results = statuses
            response.Parameters = results
            _logger.info("sending set publishing mode response")
            self.send_response(requesthdr.RequestHandle, seqhdr, response)

            _logger.warning("Unknown message received %s (%s)", typeid, user)
            raise ServiceError(ua.StatusCodes.BadServiceUnsupported)

Fixed code:
    def is_activated(self) -> bool:
        return self.state == SessionState.Activated

            # All services that requere a active session
            if not self.session:
                _logger.info("Request service that need a session (%s)", user)
                raise ServiceError(ua.StatusCodes.BadSessionIdInvalid)
            if not self.session.is_activated():
                _logger.info("Request service that needs a activated session (%s)", user)
                raise ServiceError(ua.StatusCodes.BadSessionNotActivated)

            if typeid == ua.NodeId(ua.ObjectIds.ReadRequest_Encoding_DefaultBinary):
                self._raise_error_if_session_is_invalid()
                _logger.info("Read request (%s)", user)
                params = struct_from_binary(ua.ReadParameters, body)
                results = await self.session.read(params)
                response = ua.ReadResponse()
                response.Results = results
                # _logger.info("sending read response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.WriteRequest_Encoding_DefaultBinary):
                _logger.info("Write request (%s)", user)
                params = struct_from_binary(ua.WriteParameters, body)
                results = await self.session.write(params)
                response = ua.WriteResponse()
                response.Results = results
                # _logger.info("sending write response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.BrowseRequest_Encoding_DefaultBinary):
                _logger.info("Browse request (%s)", user)
                params = struct_from_binary(ua.BrowseParameters, body)
                results = await self.session.browse(params)
                response = ua.BrowseResponse()
                response.Results = results
                # _logger.info("sending browse response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.TranslateBrowsePathsToNodeIdsRequest_Encoding_DefaultBinary):
                _logger.info("translate browsepaths to nodeids request (%s)", user)
                params = struct_from_binary(ua.TranslateBrowsePathsToNodeIdsParameters, body)
                paths = await self.session.translate_browsepaths_to_nodeids(params.BrowsePaths)
                response = ua.TranslateBrowsePathsToNodeIdsResponse()
                response.Results = paths
                # _logger.info("sending translate browsepaths to nodeids response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.AddNodesRequest_Encoding_DefaultBinary):
                _logger.info("add nodes request (%s)", user)
                params = struct_from_binary(ua.AddNodesParameters, body)
                results = await self.session.add_nodes(params.NodesToAdd)
                response = ua.AddNodesResponse()
                response.Results = results
                # _logger.info("sending add node response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.DeleteNodesRequest_Encoding_DefaultBinary):
                _logger.info("delete nodes request (%s)", user)
                params = struct_from_binary(ua.DeleteNodesParameters, body)
                results = await self.session.delete_nodes(params)
                response = ua.DeleteNodesResponse()
                response.Results = results
                # _logger.info("sending delete node response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.AddReferencesRequest_Encoding_DefaultBinary):
                _logger.info("add references request (%s)", user)
                params = struct_from_binary(ua.AddReferencesParameters, body)
                results = await self.session.add_references(params.ReferencesToAdd)
                response = ua.AddReferencesResponse()
                response.Results = results
                # _logger.info("sending add references response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.DeleteReferencesRequest_Encoding_DefaultBinary):
                _logger.info("delete references request (%s)", user)
                params = struct_from_binary(ua.DeleteReferencesParameters, body)
                results = await self.session.delete_references(params.ReferencesToDelete)
                response = ua.DeleteReferencesResponse()
                response.Parameters.Results = results
                # _logger.info("sending delete references response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.CreateSubscriptionRequest_Encoding_DefaultBinary):
                _logger.info("create subscription request (%s)", user)
                params = struct_from_binary(ua.CreateSubscriptionParameters, body)
                result = await self.session.create_subscription(params, callback=self.forward_publish_response)
                response = ua.CreateSubscriptionResponse()
                response.Parameters = result
                # _logger.info("sending create subscription response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.ModifySubscriptionRequest_Encoding_DefaultBinary):
                _logger.info("modify subscription request")
                params = struct_from_binary(ua.ModifySubscriptionParameters, body)

                result = self.session.modify_subscription(params, self.forward_publish_response)

                response = ua.ModifySubscriptionResponse()
                response.Parameters = result

                #_logger.info("sending modify subscription response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.DeleteSubscriptionsRequest_Encoding_DefaultBinary):
                _logger.info("delete subscriptions request (%s)", user)
                params = struct_from_binary(ua.DeleteSubscriptionsParameters, body)
                results = await self.session.delete_subscriptions(params.SubscriptionIds)
                response = ua.DeleteSubscriptionsResponse()
                response.Results = results
                # _logger.info("sending delete subscription response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.CreateMonitoredItemsRequest_Encoding_DefaultBinary):
                _logger.info("create monitored items request (%s)", user)
                params = struct_from_binary(ua.CreateMonitoredItemsParameters, body)
                results = await self.session.create_monitored_items(params)
                response = ua.CreateMonitoredItemsResponse()
                response.Results = results
                # _logger.info("sending create monitored items response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.ModifyMonitoredItemsRequest_Encoding_DefaultBinary):
                _logger.info("modify monitored items request (%s)", user)
                params = struct_from_binary(ua.ModifyMonitoredItemsParameters, body)
                results = await self.session.modify_monitored_items(params)
                response = ua.ModifyMonitoredItemsResponse()
                response.Results = results
                # _logger.info("sending modify monitored items response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.DeleteMonitoredItemsRequest_Encoding_DefaultBinary):
                _logger.info("delete monitored items request (%s)", user)
                params = struct_from_binary(ua.DeleteMonitoredItemsParameters, body)
                results = await self.session.delete_monitored_items(params)
                response = ua.DeleteMonitoredItemsResponse()
                response.Results = results
                # _logger.info("sending delete monitored items response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.HistoryReadRequest_Encoding_DefaultBinary):
                _logger.info("history read request (%s)", user)
                params = struct_from_binary(ua.HistoryReadParameters, body)
                results = await self.session.history_read(params)
                response = ua.HistoryReadResponse()
                response.Results = results
                # _logger.info("sending history read response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.RegisterNodesRequest_Encoding_DefaultBinary):
                _logger.info("register nodes request (%s)", user)
                params = struct_from_binary(ua.RegisterNodesParameters, body)
                _logger.info("Node registration not implemented")
                response = ua.RegisterNodesResponse()
                response.Parameters.RegisteredNodeIds = params.NodesToRegister
                # _logger.info("sending register nodes response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.UnregisterNodesRequest_Encoding_DefaultBinary):
                _logger.info("unregister nodes request (%s)", user)
                params = struct_from_binary(ua.UnregisterNodesParameters, body)
                response = ua.UnregisterNodesResponse()
                # _logger.info("sending unregister nodes response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.PublishRequest_Encoding_DefaultBinary):
                _logger.debug("publish request (%s)", user)
                if not self.session:
                    return False
                params = struct_from_binary(ua.PublishParameters, body)
                data = PublishRequestData(requesthdr=requesthdr, seqhdr=seqhdr)
                # Store the Publish Request (will be used to send publish answers from server)
                self._publish_requests.append(data)
                # If there is an enqueued result forward it immediately
                while self._publish_results:
                    result = self._publish_results.popleft()
                    if result.SubscriptionId not in self.session.subscription_service.active_subscription_ids:
                        # Discard the result if the subscription is no longer active
                        continue
                    await self.forward_publish_response(result)
                    break
                self.session.publish(params.SubscriptionAcknowledgements)
                # _logger.debug("publish forward to server")

            elif typeid == ua.NodeId(ua.ObjectIds.RepublishRequest_Encoding_DefaultBinary):
                _logger.info("re-publish request (%s)", user)
                params = struct_from_binary(ua.RepublishParameters, body)
                msg = self.session.republish(params)
                response = ua.RepublishResponse()
                response.NotificationMessage = msg
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.CallRequest_Encoding_DefaultBinary):
                _logger.info("call request (%s)", user)
                params = struct_from_binary(ua.CallParameters, body)
                results = await self.session.call(params.MethodsToCall)
                response = ua.CallResponse()
                response.Results = results
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.SetMonitoringModeRequest_Encoding_DefaultBinary):
                _logger.info("set monitoring mode request (%s)", user)
                params = struct_from_binary(ua.SetMonitoringModeParameters, body)
                # FIXME: Implement SetMonitoringMode
                # For now send dummy results to keep clients happy
                response = ua.SetMonitoringModeResponse()
                results = ua.SetMonitoringModeResult()
                ids = params.MonitoredItemIds
                statuses = [ua.StatusCode(ua.StatusCodes.Good) for node_id in ids]
                results.Results = statuses
                response.Parameters = results
                _logger.info("sending set monitoring mode response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            elif typeid == ua.NodeId(ua.ObjectIds.SetPublishingModeRequest_Encoding_DefaultBinary):
                _logger.info("set publishing mode request (%s)", user)
                params = struct_from_binary(ua.SetPublishingModeParameters, body)
                # FIXME: Implement SetPublishingMode
                # For now send dummy results to keep clients happy
                response = ua.SetPublishingModeResponse()
                results = ua.SetPublishingModeResult()
                ids = params.SubscriptionIds
                statuses = [ua.StatusCode(ua.StatusCodes.Good) for node_id in ids]
                results.Results = statuses
                response.Parameters = results
                _logger.info("sending set publishing mode response")
                self.send_response(requesthdr.RequestHandle, seqhdr, response)

            else:
                _logger.warning("Unknown message received %s (%s)", typeid, user)
                raise ServiceError(ua.StatusCodes.BadServiceUnsupported)