Su to Root

Grook93 · 08-25-2006, 07:07 PM

How do I completely disable su to root, like in a default Ubuntu installation? I'm in CentOS 4 if that matters. Thanks in advance.

bernied · 08-25-2006, 07:14 PM

In Ubuntu the only reason su is disabled is because there is no password.
So, maybe delete the password.

But make sure you've got sudo working first. To reinstate:
sudo passwd

Brian1 · 08-25-2006, 07:40 PM

Rename the /bin/su command to somthing else. Only you will know what it is.

Brian1

Grook93 · 08-25-2006, 10:19 PM

Thanks that's pretty slick.

randyding · 08-25-2006, 11:33 PM

Actually not hard to figure out.
$ strings /bin/su
will give you a signature, then test every program in /bin until you find the familiar signature.

gilead · 08-26-2006, 02:10 AM

The /etc/suauth file controls who can use su. I have the following on one of my boxes so that nobody except me can use su:

Code:

root:ALL EXCEPT steve:DENY

man suauth has more info...

magnus.therning · 08-31-2006, 11:12 AM

Quote:

Originally Posted by Grook93

How do I completely disable su to root, like in a default Ubuntu installation? I'm in CentOS 4 if that matters. Thanks in advance.

To lock the root account:

# passwd -l root

To unlock it again:

# passwd -u root

To delete a user's password:

# passwd -d root

All found in the manpage for passwd :-)