Resolved SSH no sudoers right

[Fixel]

Hi everyone,

sorry for my newbie question... Its more linux than plesk, but i hope you guys can help me!

I set up my new Server with Plesk on top of it, to make it more secure, i denied root ssh login. And allowed only one user to login via ssh.

Now I recognized, that the only user which can login over SSH has no right to perform sudo commands. I forgot the entry in the sudoers file!

My hope is to get it running any how by using the Plesk interface. I saw that It's possible to perform a command as root.

Is it possible to get my user into the sudoers with this solution? I already tried that:

echo "myuser ALL=(ALL:ALL) ALL">>/etc/sudoers

But it didn't work after restart.

Are there any ideas or solutions?

Thanks in advance.

Felix

 

[virtubox]

Hello, you can try to add sudo rights to your user by adding a cronjob woth the task manager as root.

But in my opinion, allow only ssh access for root with ssh keys and a custom ssh port should provide a good level of security without risking to loose access to your server

 

[Fixel]

Hello, you can try to add sudo rights to your user by adding a cronjob woth the task manager as root.

I already configured a cronjob filled with the command above and executed it as root. No errors, but after a reboot I still couldn't sudo. Any ideas why this didn't work? I tried it on an other machine, the entry in the file was made succesfully at the bottom.

Are there any other commands which I can use to give this user the permission to execute sudo again?

But in my opinion, allow only ssh access for root with ssh keys and a custom ssh port should provide a good level of security without risking to loose access to your server

I already configured a custom ssh port. I didn't use a ssh key so far, because I wanted to stay flexable, so I can still access it from everywhere.

But I will think about it. Thank you for the advice.

 

[virtubox]

I already configured a cronjob filled with the command above and executed it as root. No errors, but after a reboot I still couldn't sudo. Any ideas why this didn't work? I tried it on an other machine, the entry in the file was made succesfully at the bottom.

Are there any other commands which I can use to give this user the permission to execute sudo again?



I already configured a custom ssh port. I didn't use a ssh key so far, because I wanted to stay flexable, so I can still access it from everywhere.

But I will think about it. Thank you for the advice.

The cronjob used was :

 sudo adduser your_user sudo

?

Otherwise you can try to replace your sshd_config file and to restart ssh service.
I have posted the default sshd_config (with root login allowed) for ubuntu on gist.github.com : default sshd config ubuntu · GitHub

So you can create a cronjob :

wget https://gist.githubusercontent.com/VirtuBox/a2a98d9f195f38c2b17dee80a8f124d2/raw/29bfb405fdb835b5106b44aa0d3200c715240c0b/sshd_config -O /etc/ssh/sshd_config && systemctl restart ssh

 

[Fixel]

Well, thank you very much!

I tried to execute this

echo "myuser ALL=(ALL:ALL) ALL">>/etc/sudoers

to add the user manually to the file.

Didn't know there is a group for all sudo users! Need to learn more about Linux!

again, thank you, you saved me!

 

[Geoffrey]

Hi

After following the thread and the instructions therein,

I got the error

/bin/bash: /etc/sudoers permission denied

Fyi(trying to deploy a react application)(tried deploying the build folder at httpdocs (failed) trying now to deploy using the terminal on ubuntu 20.04 but can't sudo )

Any help would be greatly appreciated.

Thank you