Linux Server Security Audit Checklist

A Linux server security audit is a systematic read of a server's configuration to find settings that expose it: permissive SSH access, an inactive or over-open firewall, services listening on public interfaces, over-privileged accounts, dangerous file permissions and missing security patches. It inspects state rather than changing it, so a full audit is safe to run against production.

Audit after every change to who has access - a new hire, a departure, a contractor finishing - and after provisioning any new server. Beyond that, monthly is a reasonable baseline. The reason is configuration drift rather than new vulnerabilities: a setting relaxed for a quick test is rarely reverted, and nothing on the server reminds you.

Most of them, yes. Checks that read another account's files or the sudoers configuration need root, and are reported as skipped rather than guessed when you run without it. The rest read files that are world-readable by default, such as sshd_config and login.defs, and work as any user.

All of them in common server use. Every audit script carries a cross-distribution preamble that detects the package family for itself, covering Ubuntu, Debian, RHEL, CentOS, Rocky, Alma, Amazon Linux, Fedora, Oracle Linux, SUSE and Alpine, then adapts the commands it runs accordingly.

No. The checks are read-only: they parse configuration files and query system state, and the whole server category takes roughly a minute and a half of wall-clock time. Nothing is installed, no service is restarted and nothing is written to the host.