User and Group access restrictions?
I have read everything I can find about user and group management, but I'm still kind of unclear about a few things.
I've read many times how to use user and group add commands, but I haven't found any good explanations on how to really administer security. From the initial looks of it, linux security isn't very flexible.
I check all the execuables in the /usr/sbin directory (RH 8.0), and I see that almost every command has world execute permission - even the "useradd" command itself! This means I can add a user who can also add his own users - that seems like a major security issue.
I need to add some logins for some part time techs for some very basic monitoring, but the way it looks, they basically have free reign to do anything on the system except for just a few things.
I'm apparently missing something, as the linux group security system seems terribly unusable. in /etc/group, can you add one group to another group the same way you would add a user?
It looks like I can only assign 3 levels of permission to any directory - the user, group, and world. Well what if I have 2 different groups that need DIFFERENT levels of access to the same directory?? For example, company "owners" should have read/write to my finance directory, but account auditors should only have read access. So I have 5 owners and 15 auditors - how do I do this?
And finally - let's say I want to make all of my "sales reps" members of 5 groups. From the look of it, I have to manually add each salesperson's login to the /etc/group file for EACH group they are members of. That is just plain dumb. I should be able to hire "joebob", add him ONCE to the "salesreps" group and be done with it.
Are there any really good web references out that that clearly explain all this user/group security stuff? Anything I find explains all the command switches for "groupadd" and explains what each field in /etc/group represents and drops it at that. I need more depth.
Thanks for any help or direction!