user reboot the machine

shankarLe · 11-17-2007, 12:54 AM

Hello All,

I have a question on user administration. I've set up a linux server at home (rhel 4 as) and create a user called "test". when I login as user "test" and issue a "reboot" commmand, it works (the machine has been rebooted). How does a user reboot the linux server? how does it possible? Do we have any ways to prevent users to reboot or halt system ?

Please suggest on this,

Thanks

piratas · 11-17-2007, 03:25 AM

Only user with root privilege can do reboot, halt or poweroff. Check if you accidentally created the user belonging to adm group. Use id command to verify that.
# id test

shankarLe · 11-18-2007, 01:06 AM

Quote:

Originally Posted by piratas

Only user with root privilege can do reboot, halt or poweroff. Check if you accidentally created the user belonging to adm group. Use id command to verify that.
# id test

Hello,

I have checked the privileges on the test user, here it is
[root@localhost~]#id test
uid=503(test) gid=503(test) groups=503(test)

it is just a normal user without any root privileges. I am still wondering how this could happen?

Can anyone please help me on this, thanks in advance

shankarLe · 12-01-2007, 02:39 AM

Could someone please provide any solution or suggest me on this..

Thanks

btmiller · 12-02-2007, 12:34 AM

You could always change the permission of the halt, shutdown, and reboot commands so that a normal user can't use them. It's not uncommon for Linux to give shutdown privileges to those logged in on the console, but not remote (non-root) users.

shankarLe · 12-16-2007, 12:37 AM

Quote:

Originally Posted by btmiller

You could always change the permission of the halt, shutdown, and reboot commands so that a normal user can't use them. It's not uncommon for Linux to give shutdown privileges to those logged in on the console, but not remote (non-root) users.

I hope I did not received the right answer, but I wil try somewhere else and thanks for all support.

btmiller · 12-16-2007, 04:25 PM

Well, if the user has physical access to the machine, he can always just pull out the power plug, so ddenying him shutdown access seems rather silly. Hence my post above that Linux often gives shutdown rights to locally logged in non root users.

Tinkster · 12-16-2007, 04:46 PM

Do a

Code:

ls -l `which shutdown`

Some distros are "overly user friendly" ... not many have sane
defaults (Slackware is the only exception that instantaneously
springs to my mind).

Cheers,
Tink

shankarLe · 12-23-2007, 11:29 PM

Quote:

Originally Posted by btmiller

Well, if the user has physical access to the machine, he can always just pull out the power plug, so ddenying him shutdown access seems rather silly. Hence my post above that Linux often gives shutdown rights to locally logged in non root users.

Thanks btmiller and Tinkster for your reponses. I have now fully understand the concept. This seems to applicable only for the non root users who physically resided on the box. Thanks again...