docs-alpha.jayfield.org/TODO.md

alpha.jayfield.org — TODO

Outstanding hardening items (see README.md for the full service overview). Nothing here is urgent; all are low-risk, no-downtime changes.

• Lock down the dyndns TSIG key file permissions — done 2026-07-19 /etc/bind/dyndns.jayfield.org.key was 644 (world-readable), holding the shared secret that authenticates dynamic DNS updates for dyndns.jayfield.org with no IP-based allow-update backing it up. Fixed: chmod 640 + chown root:bind (owner was already correct), matching rndc.key's permissions.

• Suppress BIND version disclosure — done 2026-07-19 No version statement in named.conf.options, so dig CH TXT version.bind @ns1.jayfield.org leaked the exact BIND version (9.18.39) — a minor fingerprinting aid for attackers. Fixed: added version "unknown"; inside the options {} block, validated with named-checkconf, and applied via rndc reload. Verified dig CH TXT version.bind now returns "unknown".

• Add response rate limiting (RRL) — done 2026-07-19 No rate-limit {} block was configured. Since allow-query { any; } is required for a public authoritative zone, RRL is the standard mitigation against the server being used for spoofed-source DNS reflection/amplification against third parties. Fixed: added rate-limit { responses-per-second 10; window 5; } to named.conf.options, validated with named-checkconf, and applied via rndc reload. Started with conservative defaults (10/s, 5s window) — revisit if legitimate high-volume resolvers get throttled.

• Add HSTS headers to all vhosts — done 2026-07-19 No vhost sent a Strict-Transport-Security header, leaving a window for on-path SSL-stripping on a user's very first plaintext request to any domain. Fixed: added Header always set Strict-Transport-Security "max-age=63072000; includeSubDomains" to all 6 domain :443 blocks (dyndns, jayfield.org, www, mail, web, cloud) — skipped default-ssl.conf since it's the self-signed catch-all with no real trusted hostname for a browser to pin. Validated with apache2ctl configtest, applied via systemctl reload apache2, verified live with curl -sI against all 6 domains.

• jayfield.org had no :80 vhost of its own — done 2026-07-19 Bare http://jayfield.org fell through to the dyndns default vhost and redirected to the wrong domain. Fixed: added a :80 block to jayfield.org.conf redirecting to https://jayfield.org/, matching the dyndns/mail pattern. Verified: curl -sI http://jayfield.org/ → 302 with Location: https://jayfield.org/.

• SSH: disable root login + password auth — done 2026-07-19 PermitRootLogin yes and PasswordAuthentication yes were both still enabled (the "known deviation" flagged in SETUP.md §1) — every credential-stuffing bot on the internet got a real login prompt to grind against. Fixed: PermitRootLogin no, PasswordAuthentication no, PubkeyAuthentication yes in /etc/ssh/sshd_config (backed up as sshd_config.bak.20260719225249). The Match Group sftp block's own PasswordAuthentication yes was left as-is — separate, already-chrooted, no-shell/no-forwarding accounts, not part of this risk. Validated with sshd -t, applied via systemctl reload sshd, verified live with sshd -T and a fresh key-only connection before considering it done.

• fail2ban: sshd jail was evadable via low-and-slow attempts — done 2026-07-19 Default findtime=30m/maxretry=3 never triggered for 47.76.192.176, which had been hitting root/jayfield logins roughly every 33 minutes for most of a day — just outside the 30-minute window, so failures kept aging out before reaching 3 strikes. Confirmed via fail2ban.log (Found/Ban counts) that no other jail showed the same per-IP timing pattern; a separate, distributed single-shot scan on apache-noscript was noted but left open (see README.md). Fixed: /etc/fail2ban/jail.d/sshd-findtime.local overrides sshd to findtime=1d, maxretry=4, bantime=1d, kept in its own drop-in rather than editing the Debian-packaged jail file. Applied via fail2ban-client reload sshd; 47.76.192.176 was banned on its very next attempt after the change.