This is the scenario: I have a machine connected to a MQTT AWS-IoT Core broker. This machine is authorized with the AWS certificates to publish in the topic
P/serialnb/deleterecords/record_id. This topic will delete a record in the database. In a web-http architecture the user should be authorized to this transaction since it is logged with login/password and the browser/server exchange sessions between them.
Now lets say that the machine was hijacked and a hacker got access to the certificates and to the topic. So, the hacker has access to the machine serial number and the topic that delete the files in the database.
How could I mitigate this problem since the connection between machine broker has not this layer of security - only authorized users to publish in this topic?