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Got Root - Should You Use It?
vegthura asks: "I have several coworkers that insist that logging into servers is an acceptable practice. They claim it's just easier than using sudo and it's just as safe - you know you're root so what else do you need? And why bother logging in as you if you're just going to use sudo to run commands with root privileges anyway? Everything I've ever read has been the exact opposite philosophy. There is very little you need to be root to do, if anything in practice, and using sudo lets you only use the power of root for when you really need it. So, die hard unix geeks, you've got root... do you use it or stick to sudo?"
Using sudo, you can allow 'some' root commands to other users/admins without opening up the vault, and you can do a lot of smart things like keep root unable to be logged into, or have a true strong password that you can lock in a safe somewhere, all without losing functionality.
Using sudo provides a host of benefits besides giving you root. Sudo allows you to grant access to specific users for specific commands, and then revoke those commands later. Compare this with giving the root password to everyone, which requires the password to be changed whenever someone leaves the company (or someone's root privs are revoked).
/home/myusername and not /root, meaning I can get to it later.
/var/www/certs/domainname/' and it doesn't give me an error, I know that the permissions are wrong on that directory (more of a reminder than anything). I've gotten so used to this on most systems that the series of commands I use to access the IMAP virtualhost directory is essentially 'cd /var/spool/postfix/virtual; sudo bash; cd /var/spool/postfix/virtual', which slows me down surprisingly not much.
I can grant access via sudo to users for specific commands, without giving them complete administrative access to the entire system.
When I'm using 'sudo' to do things, my environment stays the same. This means that my $PATH variable stays the same, and so does my prompt. It means that any time I say ~ it refers to
When I'm not using sudo and I do 'cd
It doesn't take much to hit the up arrow, Ctrl-A, type 'sudo ' and then hit enter if you find you need to.
I can set in ~/.bash_profile that I want rm to use -i by default (alias rm='rm -i') for safety, which carries over into my 'sudo' environment; doing this for root by default can cause e.g. cronjobs to hang, waiting for input that will never come.
The benefits of sudo are not limited to 'gaining root' - they are multitudinous, and apparently your coworkers have never considered versatility to be a benefit; nor, for that matter, have they done likewise for security. Perhaps they should be educated.
I even use sudo on my *nix boxes @ home. I am a firm believer in sudo. mainly since if I do something stupid with it, I have a log of what it was. We also use sudo at work on all of our boxes(40+), to me it just makes it easier, and makes for one less password to remember. ALso the majority of tasks that I need to do, I can do as myself, there are some tasks, such as restarting services,etc that I need root to be able to do, so as opposed to su'ing over to root, (we don't allow root logins), it is just as easy to sudo the command. Once we get around to hiring a Jr admin, we will use sudo to limit what they can access.
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Whatever you do, DO NOT allow remote root logins. Ever!
root is the one account that attackers can be reasonably sure exists on your computer. Allowing remote access to it allows them to hammer it with dictionary, brute force, and social engineering attacks from relative safety.
If you're the only admin on the computer, su into root is fine - if anything goes wrong, it's your fault anyways. Otherwise, use sudo to maintain high levels of auditability and least privileged access.
-Erwos
Plausible conjecture should not be misrepresented as proof positive.
Good practice is to avoid running server tasks as root unless absolutely necessary, and there are all kinds of server admin tasks you might need to do, that don't need to involve becoming root. Database administration, for example.
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You are. The right way to say it is, "Use sudo if you only need to run one command as root; log in as root only when you're going to need to do a number of things that require root."
As a side-note, somebody upstream noted that sudo doesn't change your environment, but becoming root does. If you don't need root's environment, just use su, instead of "su -" and you keep your current location, $PATH and other things.
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You don't. Globbing is broken because the shell does it before sudo is run. This gets around the problem:
sudo "sh -c '(cd /var/spool/mqueue;egrep ^From:\ Postmaster qf*)'"
That works, but it's ugly, and I have to be able to invoke the shell with sudo in the first place.
I/O redirection is similarly broken. sudo grep root ~/cron_jobs >> /etc/crontab will fail because your shell will do the I/O redirection, not the sudo enabled grep. This works:
grep root ~/cron_jobs | sudo tee -a /etc/crontab >dev/null
This time, tee is the one appending the output, not the shell.
I use these workarounds with sudo quite a lot. It seems I need the latter more often than the former. But I stick with sudo regardless, for the shell environment consistency, and the ability to go back and see what I did wrong 12 hours after the 36 hour hacking session ended.
"Even if you are on the right track, you'll get run over if you just sit there" - Will Rogers
So far, I've only found one moderately-useful thing restricted to root: the SYN-flood DoS attack. That's no big deal.
A virus certainly doesn't need to patch the kernel or write to /bin. Those are cool tricks of course, but they don't gain any significant resources and aren't necessary for hiding from normal people.
If you force people to login as themselves and then SU (or sudo), then you know who was on the system with root when the system snarked ( And, if they use sudo instead of su, you can even have logs of the commands they used) -- it cuts down on the number of people you have to interview in the rush to figure out what broke the system.
Then, there's also the fact that if someone tricks you into doing something 'bad', it's less likely to catch you flatfooted as root if the only commands you exeute as 'root' are the ones that really need root.
As a last point: If you disable root logins (especially remote root logins), then a hacker needs to hunt down two passwords to get root access -- one for remote access and the other to get root.
Security isn't about making it impossible for an intruder to get in -- It's about making it hard enough that an attacker gives up and goes away -- even if they just go find an easier target (hi bill!).
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On systems where I'm the only user, I almost always use a non-root account to do normal tasks. sudo lets me elevate privileges for the command I need to, ie , and then drops back down so I don't forget to exit myself. sudo (generally) does not require you to retype your password for every command, there is a timer. If you're dumb|busy enough to walk away and leave your terminal unlocked, after a few minutes the next sudo attempt will ask for your password again.
One thing to remember, use visudo, not vi
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sudo su will just drop you into a root shell, but up until that point by forcing people to use sudo you gain a log of all the commands that they pass off with root privileges.
Unfortunately once someone gives the sudo su command all you see in the logs is an indication that some grabbed a root shell. I guess that it's a matter of personal preference, but I like the sudo method. I do login as root on occasion, but I like the extra warning that I might be breaking something with a chmod or mv.
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Among the many things wrong in your post, let me point out that disabling root does not imply giving all users full sudo access. In Ubuntu, your example distro, only the first user created has sudo privileges, unless they are specifically added to another account.
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$ sudo bash -c 'echo "Apr 15 22:05:41 linux-black sudo: person_you_hate : TTY=pts/0 ; PWD=/home/boss ; USER=root ; COMMAND=/bin/rm -rf /path/to/the/bosses/files" >> /path/to/the/log'
you do, of course, realise, that this command will be appended to your freshly deleted log?
It seems that this is surprising to a lot of people because nobody has mentioned this, and people have mentioned that you should never allow remote root logins, yadda, yadda.
Actually there is no problem with remote root logins via ssh and public key authentication... just don't use/allow passwords. I'm continually amazed by how few people understand this, especially considering that practically everyone and their dog already uses ssh for everything anyway (except they use it as though it was telnet... doh!). Ssh is the best thing that ever happened to Unix security, but 99% of people, including sysadmins it appears, use only 1% of its power because they do not understand public key authentication. But I digress...
Passwords are almost always security's weakest link, unless you have truly exceptional password discipline (i.e. chose a good (long, random) pw, have a different one for every account, use it only in safe contexts, never, ever, ever share it even with your twin-sister-wife-best-friend, never write it down, etc). The problem with sudo, from a security standpoint, is that it adds the weakness of every sudoer's password to the root account. Think about this... the INSECURITY of your root account is increased by the sum of all the weaknesses and password in-displine of all your sudoers.
Let me say this again... with sudo your root account's password security is worse than the worst of the passwords of all the sudoers, it accumulates all the weaknesses, all the indiscretions of all your sudoers.
And don't give me any crap about limiting what commands a sudoer can invoke... with sudo any command/program that isn't specifically written to be a
To their credit most of the people who wrote here that they like sudo like it for the convenience of logging priviledged actions. This is certainly a good practice. Just understand that it is a PRACTICE, not a security feature... if someone wants to get around it, they trivially can. If you want to log for security you have to do it in the kernel and most Unix kernels have such features nowadays.
So, if you want convenient logging of your own actions, go ahead and use sudo. If you want to
Btw., some ssh implementations can do everything you
What does matter, is accounting for which user ran that "rm -rf /mnt/financialReports" and isn't owning up to it. Or which user made system tuning changes that don't seem to be working right. Or any number of things which may or may not be malicious, but need questions answered.
None of the companies I worked for put sudo on servers to limit what their sys admins could do - they put it on the systems so that they could, if something were to happen, figure out which of their admins they needed to go ask questions of. Files are missing, what were you doing. Server isn't behaving right any more, what was the last thing you worked on.
You can't do any of this (easily) if 5 admins are all logging in as the same user. You can do it fairly trivially if you're logging in as your own id and switching to root.
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sudo provides much more than su...
1. It authenticates against the same password that you logged in with, not only saving you from learning two, but allowing you to keep the root password secret.
2. It doesnt always have to allow access to root, "sudo -u user" can be used to give application/db access.
3. sudo remembers your access for a little while, allowing you to single-shot commands, causing less irritation than "su -c"
4. You can control it remotely, e.g. by active directory group. This allows centralised user administration of system admins.
5. You can provide privileged access of single shot commands to batch processes.
-- Don't believe everything you read, hear or think
No one ever seems to mention this, but for me I use su with the coworkers who have root access. Reason? Pure and simple, I get to set the root password, and I set it hard. For various reasons having to do with parts of the computing environment I don't control, I can't have the same confidence about non-root passwords.
Using su instead of sudo puts one more barrier in the way. If you cracked a regular user account with liberal sudo access but a weak password, the same weak password gets you to root. That isn't true with su.