Abstract—Open ports are typically used by server software to serve remote clients, and the usage historically leads to remote exploitation due to insufficient protection. Smartphone operating systems inherit the open port support, but since they are significantly different from traditional server machines in performance and availability guarantees, little is known about how smartphone applications use open ports and what the security implications are.

https://eecs.umich.edu/eecs/about/articles/2017/open_euro17.pdf