Discussion on rubynz

It seems to be common advice to deactivate the root user on Linux servers such that you can’t log in as root no matter the authentication method (e.g. password, key based, …). AWS EC2 instances use ubuntu by default instead of root. So my question is, do you follow the advice to begin with? If so, do you deactivate the ubuntu user as well? What other countermeasures do you take to secure root like accounts?

nickmalcolm [10:53 AM] It’s worth noting that ubuntu isn’t root, but that ubuntu can sudo to become root.

[10:53] I hadn’t actually considered why though - I figured it was just a bit of obfuscation / another ACL layer to go through, opportunity to catch baddies, log baddies, etc

ur5us [10:56 AM] yes, ubuntu is not root but sudo-ing doesn’t require you to type a password

[10:56] AFAIK, yes, originally it’s just an obfuscation pattern hence why I question its usefulness

terrcin [10:59 AM] could change it to require a password

td512 [10:59 AM] @ur5us my usual process:

  • Log in to ubuntu
  • Change root's password
  • Log in as root
  • Terminate ubuntu
  • Add my (16384-bit) SSH-key to root
  • Change the root's password to a random 128 character password
  • Edit /etc/ssh/sshd_config to suit (and restart sshd)
  • Update the OS
  • Reboot the machine
  • Install KernelCare
  • Change shell to mksh
  • Install packages I need
  • Create new passwordless user and add my (8192-bit) key to it
  • Run anything I need to as said passwordless user

terrcin [11:00 AM] that's typically what I've done in the past. no root login, have a different account for login that can sudo, but with a password

[11:00] I've noticed that when using other services that set up stuff for me that you can shell in with root, but the account you do use has sudo without password.

td512 [11:02 AM] @terrcin that would be security by design. Launch as root to bind to a port less than 1024 and drop all privs so if the service gets hacked, it only affects said service :stuck_out_tongue:

[11:02] unless you're MySQL, in which case you have no good reason for running as root

ur5us [11:03 AM] @td512 so you do get rid of the default ubuntu user. I assume you also disallow logging in via root user, or?

td512 [11:03 AM] oh yeah, and change the default db password or bind to exclusively

[11:04] @ur5us when I say

  • Edit /etc/ssh/sshd_config to suit (and restart sshd) I mean I disallow all password based logins

[11:04] so unless you have my keys, you're not getting in

ur5us [11:07 AM] @td512 Sure, I get that part, I mean no password based logins. Until now I usually turn off root user logins as well, so I can’t ssh [email protected]. But that can be a PITA if you use Ansible and the Ansible user requires typing the password to become root user every time

td512 [11:08 AM] I don't personally. that's a really bad idea if you need to recover something

[11:09] my "fix" is to lock sshd down until only I can login as root (edited)

ur5us [11:09 AM] @td512 ok, thanks

rose [11:39 AM] uploaded and commented on this image: Screen Shot 2017-04-21 at 10.54.32 AM.png 1 Comment Is anyone using pry-remote with foreman? When I try and connect to the remote session I’m getting this error

new messages jonrowe [11:51 AM] Personally I’d never allow someone to ssh in as root, too much accidental privileges, I think you’ll always be able to sudo su root but you can limit sudo powers and add password etc to make it harder

danielfone [11:59 AM] :point_up: this I think. I always understood the disabling of the root account as privilege separation rather than obfuscation. If I need privilege, I have to sudo.

charlespeach [12:02 PM] Same. I always do this in sshd_config: PermitRootLogin no

jonrowe [12:10 PM] I have password less sudo for my deploy user, but it’s limited to restarting services

ur5us [1:01 PM] @charlespeach so you always type the password to become sudo when running Ansible?