Linux – Best practice for multi Admin root access

linuxroot

I'm trying to put together a security policy for a collection of Linux servers. There are 8 people in my organization that require root level access over SSH.

At a past company, my solution was to permit only RSA keys and give everyone a user with their own key.

To grant root privileges, I set the UID to 0. This negated needing to setup sudo or su which people just seem to sudo su – or sudo /bin/bash anyway. It also let me do the following.

I patched Bash to log the return value of getlogin() and the command to syslog. I then had a log of everything run on the servers and usernames tied to users. If I used su or sudo, I would just get the user root.

I'm in a fresh state right now at a new company and wondering if anyone has a policy they use and like.

Best Answer

We use sudo configured to allow commands from the group. To prevent the sudo -i or sudo bash, I have setup an alias including all known shells which I disallow using ! in the definition of what the group can do. That way, all commands run with sudo are logged to syslog. The only shell I have installed and allowed is rootsh, which logs everything done from it.

Cmnd_Alias SHELLS= /bin/sh, /bin/ksh, /bin/bash, /bin/zsh, /bin/csh, /bin/tcsh, /bin/login, /bin/su
%admin ALL = (ALL) ALL, !SHELLS

Obviously, nothing can stop an admin to

cp /bin/bash /tmp/shell
sudo /tmp/shell

in order to bypass this security, but still you give them root rights, you have to trust them anyway...

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