Publicly exposing your Linux infrastructure creates a roadmap for attackers....

https://wiki-stock.win/index.php/CI/CD_Account_Takeover:_Why_Your_%22Private%22_Email_is_the_New_Front_Door

Publicly exposing your Linux infrastructure creates a roadmap for attackers. When you leave SSH ports open to the world, bots immediately start hammering your login prompts with automated credential stuffing attacks