Security & TLS · medium · solved in-browser (no VM needed) · 3 tiered hints
Write /etc/sudoers.d/00-defaults, a sudoers drop-in of Defaults lines that: keep a secure PATH via 'Defaults secure_path="/usr/sbin:/usr/bin:/sbin:/bin"', require a tty for sudo with 'Defaults requiretty', and log sudo I/O to /var/log/sudo-io with 'Defaults log_output' and 'Defaults iolog_dir=/var/log/sudo-io'. (Authored config, graded structurally — the engine isn't run here.)
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Certificates, signatures, hardening sshd and verifying trust.
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