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NutsNews Backend Security Baseline

This tracks backend host security desired state for ramideltoro/nutsnews-backend and 65.75.201.18.

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This tracks backend host security desired state for ramideltoro/nutsnews-backend and 65.75.201.18.

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NutsNews Backend Security Baseline

This tracks backend host security desired state for ramideltoro/nutsnews-backend and 65.75.201.18.

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  accTitle: NutsNews Backend Security Baseline
  accDescr {
    This tracks backend host security desired state for ramideltoro/nutsnews-backend and 65.75.201.18.
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  A["NutsNews Backend Security Baseline"] --> B["NUTSNEWS_BACKEND_SECURITY_BASELINE.md"]
  B --> C["Auto-generated placeholder diagram"]

NutsNews Backend Security Baseline

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NutsNews Backend Security Baseline

Section titled “NutsNews Backend Security Baseline”

This tracks backend host security desired state for ramideltoro/nutsnews-backend and 65.75.201.18.

SSH Hardening

Section titled “SSH Hardening”

Backend issue #1 adds repo-managed SSH hardening through the backend Ansible baseline role.

Desired effective SSH values:

permitrootlogin no
passwordauthentication no
kbdinteractiveauthentication no
pubkeyauthentication yes

Implementation shape:

  • Comment managed auth directives in /etc/ssh/sshd_config so main-file provider defaults cannot win.
  • Install /etc/ssh/sshd_config.d/00-nutsnews-hardening.conf.
  • Validate sshd config with sshd -t before reload.
  • Apply only through the protected backend workflow.

Verification after approved apply:

Terminal window
sudo sshd -T | grep -E '^(permitrootlogin|passwordauthentication|kbdinteractiveauthentication|pubkeyauthentication) '
ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no -o BatchMode=yes rami@65.75.201.18 true
ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no -o BatchMode=yes root@65.75.201.18 true
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'hostname && whoami'

OS Package Maintenance And Reboot

Section titled “OS Package Maintenance And Reboot”

Backend issue #2 adds repo-managed OS package maintenance through the backend Ansible baseline role.

Implementation shape:

  • Refresh apt metadata.
  • Apply available package upgrades with upgrade: dist.
  • Remove unused packages and clean apt cache.
  • Reboot during real apply mode when /var/run/reboot-required exists.
  • Capture package, kernel, reboot-required, and failed-unit evidence in workflow logs.

Verification after approved apply:

Terminal window
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'uname -r'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'test ! -e /var/run/reboot-required && echo no-reboot-required'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'apt list --upgradable 2>/dev/null'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'systemctl --failed --no-pager'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'hostname && whoami'

UFW Firewall Baseline

Section titled “UFW Firewall Baseline”

Backend issue #3 adds repo-managed UFW policy through the backend Ansible baseline role.

Current public port policy:

PortProtocolPurpose
22TCPSSH

Implementation shape:

  • Install UFW.
  • Set IPV6=yes in /etc/default/ufw.
  • Reset UFW rules during approved apply.
  • Set default incoming policy to deny.
  • Set default outgoing policy to allow.
  • Allow only TCP 22 in the current phase.
  • Keep 80/tcp and 443/tcp disabled until a reviewed reverse-proxy/routing PR enables them.
  • Capture ufw status verbose in workflow logs.

Verification after approved apply:

Terminal window
sudo ufw status verbose
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'ss -tulpen 2>/dev/null || ss -tulpn'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'hostname && whoami'

SSH Brute-Force Protection

Section titled “SSH Brute-Force Protection”

Backend issue #4 adds repo-managed fail2ban protection for SSH through the backend Ansible baseline role.

Implementation shape:

  • Install fail2ban.
  • Write /etc/fail2ban/jail.d/nutsnews-sshd.local.
  • Enable the sshd jail with the systemd backend.
  • Use maxretry = 5, findtime = 10m, and bantime = 1h.
  • Ignore localhost addresses.
  • Enable and start the fail2ban service.
  • Capture fail2ban-client status sshd in workflow logs.

Verification after approved apply:

Terminal window
sudo fail2ban-client status sshd
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'hostname && whoami'
sudo fail2ban-client set sshd unbanip <ip-address>

Controlled ban testing should use a disposable test source IP and immediately unban that IP afterward.

Abuse Protection Decision

Section titled “Abuse Protection Decision”

Backend issue #24 records the broader abuse-protection decision for the current SSH-only backend phase. Backend issue #40 adds detection/report-only maintenance automation for abuse signals.

Decision:

  • Keep fail2ban as the selected tool for SSH protection.
  • Surface SSH authentication failure spikes and fail2ban SSH ban events through Grafana/Loki detection alerts.
  • Defer CrowdSec, Cloudflare blocking rules, and HTTP/Caddy enforcement until backend app routes, app/admin probes, and real route logs exist.
  • Start any future HTTP abuse controls in detection/report-only mode before blocking.
  • Do not run a protected apply, restart, firewall mutation, or production enforcement change without separate explicit approval.

Detection alert UIDs:

  • nn-backend-ssh-auth-spike
  • nn-backend-fail2ban-ban-events

These alerts use low-cardinality Loki queries scoped to host="backend.nutsnews.com" and service="security". They do not group or route on IP address, path, user, request ID, or raw message text.

Current allowlist policy:

  • SSH jail allowlist is localhost-only: 127.0.0.1/8 and ::1.
  • Cloudflare edge ranges, GitHub Actions callbacks, uptime probes, and operator ranges must be documented before any future HTTP enforcement.
  • Operator IPs must not be committed unless there is a reviewed operational reason.

False-positive-sensitive probes required before future HTTP blocking:

  • /health
  • /healthz
  • /readyz
  • auth provider redirects/callbacks
  • admin redirects and dashboard access boundaries

Backend validation:

Terminal window
python3 scripts/validate_abuse_protection_decision.py
python3 scripts/provision_grafana_metrics.py --check

Swap Safety Buffer

Section titled “Swap Safety Buffer”

Backend issue #5 adds a small persistent swapfile through the backend Ansible baseline role.

Decision:

  • Use a 2 GiB disk swapfile at /swapfile.
  • Use vm.swappiness = 10.
  • Prefer swapfile over zram for now because it is simple to inspect, persist, disable, and recover on this fresh host with ample disk.

Implementation shape:

  • Create /swapfile.
  • Set root ownership and 0600 permissions.
  • Format with mkswap when newly created.
  • Add /swapfile none swap sw 0 0 to /etc/fstab.
  • Enable swap during real apply mode.
  • Write /etc/sysctl.d/99-nutsnews-backend-swap.conf.
  • Capture swapon --show and free -h in workflow logs.

Verification after approved apply:

Terminal window
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'swapon --show'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'free -h'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'grep -E "^/swapfile\\s+none\\s+swap\\s+" /etc/fstab'
ssh -i ~/.ssh/servercheap_65_75_201_18 rami@65.75.201.18 'cat /proc/sys/vm/swappiness'

Current Blocker

Section titled “Current Blocker”

SSH hardening, OS package maintenance, UFW firewall baseline, fail2ban SSH protection, and swap baseline cannot be considered complete until the production-backend Environment and required secrets exist, the protected workflow applies the role, and read-only audits confirm the effective server state.