Which user accts in Redhat safe to delete?

scottjwoodford · 06-07-2005, 10:25 AM

I'm trying to figure out which accounts are safe to delete. Is there a list posted somewhere about what each does? Some of them have descriptions, but most of them do not. My system is RedHat 9.0.

slightcrazed · 06-07-2005, 12:04 PM

Why would you want to delete the system acounts? Usually, removing the daemon will also remove the user that was created for that daemon (i.e., if you remove sendmail then any user created during installation of sendmail will also be removed). At least, AFAIK. So if you have daemons that you don't use then just remove the daemon and it should clean up the users as well.

slight

scottjwoodford · 06-07-2005, 12:50 PM

Well, it's a security risk to leave open every account that is installed by default. Especially certain system accounts that have elevated priviledges. I can certainly remove the daemon for each, but there is no daemon for accounts like "nobody". It's similar to disabling the "guest" account in Windows. It's just good security practice.

Frankablu · 06-07-2005, 02:47 PM

If you remove the nobody account some services will run as root which is probaility what you don't want

User accounts don't generally have elevated privledges (read never).

Services start as root then when they have finished doing all the root tasks needed (i.e. opening a port below 1024) they drop root and go to their own user account which "owns" all the files it needs to work and run normally.

All elevated privedges as far as I know are stored in /etc/sudoers

slightcrazed · 06-07-2005, 04:36 PM

This is the way I understood it as well. Specialized acounts (especially daemon accounts) do not pose the same security risk as they do on a windoze box. I have never heard of this being 'good practice' or proactive in any manner. The more important thing is to eliminate, or at least not run, any services that you don't need. Those services may have security holes that allow buffer overflows and the like, and that is a much bigger security problem then someone trying to log in as 'nobody'.

slight

scottjwoodford · 06-11-2005, 10:21 AM

Well, I will tell you that I am sort of ignorant when it comes to this suject. I do know for a fact, however, that in IRIX it is unsafe to leave accounts like "nobody" and "games" unlocked unless you absolutely need them. That comes straight from SGI's IRIX security guides. I figured it was the same in Linux, but you guys may be right. Thanks for the help.