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 these accounts, 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.