Here is a script in Bash that logs in to an Ubuntu server via SSH and resets the root password:
#!/bin/bash
# Variables for the remote server login
user=<username>
server=<server_ip_or_hostname>
# Connect to the remote server using SSH
ssh $user@$server << EOF
# Switch to the root user
sudo su
# Reset the root password
echo "root:<new_password>" | chpasswd
EOF
Replace the placeholders <username>, <server_ip_or_hostname>, and <new_password> with the appropriate values for your setup. Then, save the script to a file and make it executable with the chmod +x command. You can then run the script from the terminal.
Note that this script assumes that you have SSH access to the server with a user account that has sudo privileges. Also, be careful when using this script, as it resets the root password, which is a critical operation. Make sure to test the script in a safe environment before using it in production.