Adding to Root Group using usermod

 

Method  1: Adding to Root Group using usermod

Let see how we can grant normal user root access by adding to root group.

# adduser user1
# adduser user2
# groupadd test

These are the groups I have in my Linux box.

# groups
root bin daemon sys adm disk wheel

I am going to add user1 to root group as follows:

# usermod -G root user1

The command given below provides the existing user with the root privilege

# usermod -g 0 -o root_user

Method 2: Adding to Root Group using Useradd Command

I have added a new user, 'user3' to the root group using one single command:

# useradd -m -G root user3
# groups user3
user3 : user3 root

Another option using useradd command

useradd -c “Imitation Root” -d /home/root_user -m -k /etc/skel -s /bin/bash -u 0 -o -g root root_user

Method 3: Editing /etc/passwd file

Edit /etc/passwd for the particular user. Change the user's UID and GID to '0'. This will give root permissions to user.

root:x:0:0:root:/root:/bin/bash
temproot:x:128:128:temproot

Now, temproot user should have root privilege:

root:x:0:0:root:/root:/bin/bash
temproot:x:0:0:temproot

Note: This is not the recommended method for granting root access

Method 4: Setting as Sudo User

The sudo configuration file is /etc/sudoers and you can edit this file using visudo command: # visudo.

Using visudo protects from conflicts and guarantees that the right syntax is used.

To give full access to specific users

Add the entry given below in the file:

bob, tom ALL=(ALL) ALL

Following this method is not a good idea because this allows both bob and tom to use the su command to grant themselves permanent root privileges. Thereby skipping the command logging features of sudo.

Granting access to specific files to one particular user

This entry allows bob and all the other members of the group operator to gain access to all the program files in the /sbin and /usr/sbin directories, as well as the privilege of running the command /usr/oracle/backup.pl.

bob, %operator ALL= /sbin/, /usr/sbin, /usr/oracle/backup.pl

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