Idea Of a Linux Account

The idea of a Linux Account-general Linux technology-Linux technology and application information. The following is a detailed description. Before winning the school email system
I want to log on with some built-in system accounts through ssh.
For example, tomcat mysql
But I also thought it was impossible to have such a mentally retarded vulnerability.
No default password will be given.

Read a book today
Sure enough
The encrypted passwords of those accounts are set to one character.
In this way, no password can be entered.

But vice versa
After intrusion, You can reset the passwords of these accounts as backdoors.
It is feasible for inexperienced administrators.
But experience tells me
You can never think the Administrator is more stupid than you.
The system administrator may have grown from a random intrusion like me.
Never underestimate others
Otherwise, the cost is painful.
I think about the miserable situation of freshman sniffing passwords in the school room.
Amitabha
Be careful