Performing Security Hardening on the Account UID

Accounts with a UID of 0 possess the highest system privileges, and it must be ensured that only one such account exists. Among them, only root is the super privileged user in Linux systems. Ensure that only the root account has a UID of 0 in the current system. Meanwhile, the UID of each system account must be unique. You can run the id command to query the UID of a user.