Honeywell Alerton Ascent Control Module (ACM) through 2022-05-04 allows unauthenticated programming writes from remote users. This enables code to be store on the controller and then run without verification. A user with malicious intent can send a crafted packet to change and/or stop the program without the knowledge of other users, altering the controller's function. After the programming change, the program needs to be overwritten in order for the controller to restore its original operational function.