Account Restrictions

• All admins have their own account on the system.
• Disallow root access, except via sudo.
• Disallow sudo access. Yes, this make things more difficult, but
• traceability is needed when there are multiple admins. Note: I could be coaxed off this requirement if sudo would fire up a capture program (like script) when 'sudo ' is used. -- BenScott - 08 Feb 2006
• I much prefer autostarting script if 'sudo shell' is run - flexible and easy. Creating time/original user named logfile in standard location would be ideal. (e.g. 2006_02_10_11_53_billm.log) -- DrewVanZandt - 10 Feb 2006
• Some things that require shell redirection don't work without this - however those can be put into a script and run 'sudo script'. But then the script is fungable after the run, so what's been gained is worth debating. -- BillMcGonigle - 08 Feb 2006

Firewall

• iptables - unless there is some other level of firewalling available to us.
  • even if there is a hardware firewall, don't trust it. To expound, only allow incoming access on the minimum number of ports to get us going. We should restrict ssh access to a limited number of IP's to avoid being DDOS'ed with ssh scans. -- BillMcGonigle - 09 Feb 2006
  • Allowed Ports From Anywhere
    • 25/tcp
    • 80/tcp
    • 443/tcp
    • 53/udp
  • Allowed IP's for port 22 ssh
    • 217.160.248.65 -- BillMcGonigle - 09 Feb 2006
    • Recommend moving SSH to nonstandard port. Scripted attacks only hit 22. -- DrewVanZandt - 10 Feb 2006
      • I've been port-scanned for ssh running on non-standard ports. -- BillMcGonigle - 11 Feb 2006
    • All except non-routable IP's. But run ssh on a non-standard, non-privileged port.
      • I postulate that restricting ssh access to a small set of IP's is more secure than having it open to the world. It avoids all the script-kiddie issues, for instance. So, there should be arguments here for why we'd want to accept a less-secure method in the face of known attacks. -- BillMcGonigle - 11 Feb 2006
    • Suggest running SSH on a nonstandard port -- ColeTuininga - 10 Feb 2006
  • Allowed Ports for our backup DNS, currenly LINUX.CODEMETA.COM (199.125.76.10)
    • 53/tcp

Remote Access

• SSH - Require public key authentication, require entries in AllowedUsers in sshd_config. Inconvenient for adding new accounts, but the number of accounts will be very low and we don't have time to deal with getting cracked. -- BillMcGonigle - 11 Feb 2006
• Opinion - I am aware this could cause flames, sorry. Cracking will probably not be from password guessing etc. (especially if on nonstandard port, and we stick to decent passwords e.g. gpw or whatever) - it will be a vulnerability in a service we run. Minimal exposure to the outside world would be good. :-)