WordPress 6.9

Check that Apache and MySQL are listening and that WP-CLI works:

sudo systemctl status apache2 --no-pager | head -10 sudo ss -tlnp | grep -E ':(80|3306) '
sudo /usr/local/bin/wp --info --allow-root --path=/var/www/html/wordpress | head -10

Check the WordPress version, the posts and the users:

sudo -u www-data /usr/local/bin/wp core version --path=/var/www/html/wordpress sudo -u www-data /usr/local/bin/wp post list --path=/var/www/html/wordpress sudo -u www-data /usr/local/bin/wp user list --path=/var/www/html/wordpress

sudo cat /stage/scripts/wordpress-credentials.log

Find WP_ADMIN_PASSWORD and WP_ADMIN_URL in the file.

Browse to http://<vm-ip>/ to see the WordPress front end with the default Hello World post.

Browse to http://<vm-ip>/wp-admin/ (or /wp-login.php) and sign in as SecureAnyCloud with the password from Step 6.

The dashboard shows site activity, recent comments, unpublished posts and quick publish.

A default WordPress install ships with two bundled plugins, Akismet and Hello Dolly. Add more under Plugins > Add New.

These are the key paths and files on the VM:

• WordPress install: /var/www/html/wordpress/
• wp-config.php: /var/www/html/wordpress/wp-config.php
• Apache virtual host: /etc/apache2/sites-available/wordpress.conf
• Apache logs: /var/log/apache2/wordpress-{access,error}.log
• MySQL data: /var/lib/mysql/
• WP-CLI: /usr/local/bin/wp
• First boot script: /usr/local/sbin/wordpress-firstboot.sh
• Credentials: /stage/scripts/wordpress-credentials.log (mode 0600 root:root)

• Enable HTTPS. Install certbot and obtain a Let's Encrypt certificate: sudo apt-get install -y certbot python3-certbot-apache && sudo certbot --apache
• Restrict the network security group. Open port 80 only to your CDN, load balancer or Cloudflare, and keep port 22 open to your management CIDR only.
• Update plugins and themes monthly with wp plugin update --all and wp theme update --all.
• Enable two-factor authentication with the Wordfence or Two Factor Authentication plugin.
• Patch monthly: apt-get update && apt-get upgrade && reboot

In the AWS Marketplace listing, choose Continue to Subscribe, then Continue to Configuration. Pick WordPress 6.9 on Ubuntu 24.04 as the software version and select your Region. Then choose Launch through EC2.

Choose m5.large, your key pair and a security group as above.

Or launch with the AWS CLI, replacing the values in angle brackets:

aws ec2 run-instances --region <region> --image-id <ami-id-from-the-listing> \
  --instance-type m5.large --key-name <your-key-pair> \
  --security-group-ids <your-security-group> --subnet-id <your-subnet> \
  --metadata-options HttpTokens=required,HttpEndpoint=enabled \
  --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=wordpress}]'

For WordPress 6.9 on Ubuntu 24.04, the SSH user is ubuntu. Connect with:

ssh -i <your-key.pem> ubuntu@<public-ip>

First boot takes under a minute. It creates the database and runs WordPress's installer. Then nginx, PHP, MariaDB, the first boot unit and the timer for WordPress's scheduled jobs are active:

systemctl is-active nginx php8.3-fpm mariadb wordpress-firstboot wordpress-cron.timer

active active active active active

nginx serves ports 80 and 443. PHP and MariaDB listen on local sockets only, so the only open ports are 22, 80 and 443:

sudo ss -tlnp | awk 'NR==1 || /nginx|sshd|php|maria/' | awk '{print $1, $4, $6}' | sed -E 's/,pid=[0-9]+,fd=[0-9]+//g'

State Local Peer LISTEN 0.0.0.0:22 users:(("sshd"),("systemd")) LISTEN 0.0.0.0:80 users:(("nginx"),("nginx"),("nginx")) LISTEN 0.0.0.0:443 users:(("nginx"),("nginx"),("nginx")) LISTEN [::]:22 users:(("sshd"),("systemd")) LISTEN [::]:80 users:(("nginx"),("nginx"),("nginx")) LISTEN [::]:443 users:(("nginx"),("nginx"),("nginx"))

These commands show the WordPress release, the PHP and MariaDB versions, and how the downloads were verified:

sudo wp core version --extra php -v | head -1 mariadb --version cat /usr/share/doc/sac-wordpress/RELEASE

WordPress version: 6.9.11 Database revision: 60717 TinyMCE version: 4.9110 (49110-20250317) Package language: en_US PHP 8.3.6 (cli) (built: Oct 19 2026 15:16:58) (NTS) mariadb Ver 15.1 Distrib 10.11.14-MariaDB, for debian-linux-gnu (x86_64) using EditLine wrapper WordPress 6.9.11 source https://wordpress.org/wordpress-6.9.11.tar.gz sha256 b870d073d15d4573373bcee961b9eecec8b1063aabf26335bd964898b0d7710a sha1 38e46b10acb2fe37ab20930f222075b9ee7e080d WP-CLI 2.12.0 (https://github.com/wp-cli/wp-cli/releases/download/v2.12.0/wp-cli-2.12.0.phar, sha256 ce34ddd838f7351d6759068d09793f26755463b4a4610a5a5c0a97b68220d85c) theme: Twenty Twenty-Five 1.5 (https://downloads.wordpress.org/theme/twentytwentyfive.1.5.zip, sha256 f333ce53aaa4049639298247d03480a4bd9b56fa8f0fea0440da262d7d595ba4) not shipped: Akismet, Hello Dolly, Twenty Twenty-Three, Twenty Twenty-Four option B (TinyMCE 4.9.11 off by default): /usr/local/lib/sac/wordpress/mu-plugins/sac-wp-no-tinymce.php + /etc/nginx/snippets/sac-wp-no-tinymce.conf

The credentials file holds the address WordPress is served as (your instance's public DNS name by default), the administration address, the administrator's user name, email and password, and the database credentials. All of them are generated on this instance. Show the file with:

sudo cat /root/wordpress-credentials.txt

WORDPRESS_URL=https://ec2-<public-ip-dashed>.<region>.compute.amazonaws.com/ WORDPRESS_ADMIN_URL=https://ec2-<public-ip-dashed>.<region>.compute.amazonaws.com/wp-admin/ WORDPRESS_ADMIN_USER=sac WORDPRESS_ADMIN_PASSWORD=<24 letters and digits> WORDPRESS_ADMIN_EMAIL=admin@example.com WORDPRESS_DB_NAME=wordpress WORDPRESS_DB_USER=wordpress WORDPRESS_DB_PASSWORD=<48 letters and digits>

The administrator starts with the email admin@example.com and the display name Site Administrator. Change both to your own under Users > Profile before you rely on WordPress's password emails. Its public author name (site-admin) is not the sign-in name.

Open WORDPRESS_URL in your browser. The certificate is self-signed (generated on your instance), so your browser warns once. Compare the certificate's SHA-256 fingerprint with the one on the instance (sudo openssl x509 -in /etc/nginx/ssl/wordpress.crt -noout -fingerprint -sha256) and continue, or install a certificate from your own certificate authority (Step 12). A fresh site shows the Twenty Twenty-Five theme with WordPress's Hello world! post:

Open WORDPRESS_ADMIN_URL and sign in with WORDPRESS_ADMIN_USER and WORDPRESS_ADMIN_PASSWORD:

The dashboard opens with WordPress's welcome panel and the admin menu on the left:

The dashboard may say that a newer major WordPress release (7.x) is available. A major upgrade is your decision, not an automatic update (Step 10).

Posts lists your posts (a fresh site has WordPress's Hello world!). Choose Add Post to open a new one:

Posts and pages open in the block editor. Add paragraphs, headings, images, galleries, columns, buttons and patterns from the + inserter:

Appearance > Editor opens the Site Editor, where you design the theme's templates, header, footer, colours and fonts with the same blocks:

Why there is no Classic editor. WordPress 6.9 still ships TinyMCE 4.9.11, the editor behind the Classic (visual) editor and the Classic block. TinyMCE 4.x has published high-severity stored cross-site scripting advisories (CVE-2026-47759, CVE-2026-47761 and CVE-2026-47762) and no 4.x release fixes them. A user who can write posts could store content that runs script in an editor's browser when the Classic editor opens it. So this image keeps TinyMCE unreachable by default, in two independent layers:

• Must-use plugin. The sac-wp-no-tinymce plugin (in /usr/local/lib/sac/wordpress/mu-plugins, owned by root, outside the web root, with no deactivate switch in the admin area) turns the visual editor off for every user, removes the Classic block and the old editor scripts, and keeps every editing screen on the block editor.
• nginx rule. nginx refuses every TinyMCE file, in every spelling, and the script loader that could bundle it.

The block editor, the Site Editor, comments and the text-mode (HTML) editors keep working. Older posts written in the Classic editor open in the block editor, where their content is kept as HTML you can convert to blocks.

sudo wp plugin list --status=must-use --fields=name,status sudo wp theme list --fields=name,status,version
H=$(sed -n 's/^set \$wp_host "\(.*\)";$/\1/p' /etc/nginx/wordpress-host.conf) for p in /wp-includes/js/tinymce/tinymce.min.js /wp-includes/js/tinymce/wp-tinymce.php /WP-INCLUDES/JS/TINYMCE/tinymce.min.js "/wp-admin/load-scripts.php?load%5Bchunk_0%5D=wp-tinymce" /wp-includes/js/jquery/jquery.min.js; do curl -sk -o /dev/null -w "$p: %{http_code}\n" --resolve "$H:443:127.0.0.1" "https://$H$p" done

name status sac-wp-no-tinymce must-use sac-wordpress-hardening must-use name status version twentytwentyfive active 1.5 /wp-includes/js/tinymce/tinymce.min.js: 403 /wp-includes/js/tinymce/wp-tinymce.php: 403 /WP-INCLUDES/JS/TINYMCE/tinymce.min.js: 403 /wp-admin/load-scripts.php?load%5Bchunk_0%5D=wp-tinymce: 403 /wp-includes/js/jquery/jquery.min.js: 200

403 is nginx refusing the file. jQuery, which the admin area needs, still loads.

What re-opens the advisories. The protection covers WordPress as shipped. Re-enabling the Classic editor brings back TinyMCE 4.9.11 and its unfixed stored cross-site scripting advisories. The Classic Editor plugin uses core's TinyMCE (off while user_can_richedit is false), so re-enabling it together with removing the mu-plugin brings TinyMCE back. So does removing sac-wp-no-tinymce.php or the nginx rule /etc/nginx/snippets/sac-wp-no-tinymce.conf, or adding a plugin or theme that brings its own copy of TinyMCE (for example a page builder or form plugin with a visual editor).

SecureAnyCloud recommends keeping the Classic editor off until WordPress ships a fixed editor. If you need it in the meantime, give only trusted users the right to write posts, and check the release notes of each WordPress upgrade (Step 10).

These are the image defaults and where to change each one:

• Permalinks: /%postname%/. Change it under Settings > Permalinks.
• Anyone can register: off. Change it under Settings > General.
• Pingbacks and trackbacks: off. Change them under Settings > Discussion.
• Avatars (Gravatar): off. Change them under Settings > Discussion.
• Time zone: UTC. Change it under Settings > General.
• XML-RPC and application passwords: off. Change them in the must-use plugin sac-wordpress-hardening.php.
• Theme and plugin file editor: off (DISALLOW_FILE_EDIT). Change it in wp-config.php.
• Automatic core updates: minor (6.9.x) releases. Change them in wp-config.php (WP_AUTO_UPDATE_CORE).

sudo wp option get permalink_structure for o in users_can_register default_ping_status default_pingback_flag show_avatars timezone_string blog_public; do printf '%s=%s\n' "$o" "$(sudo wp option get $o)"; done
sudo grep -E "^define\( '(WP_AUTO_UPDATE_CORE|DISALLOW_FILE_EDIT|DISABLE_WP_CRON|FS_METHOD|FORCE_SSL_ADMIN|WPMU_PLUGIN_DIR)'" /var/www/wp-config.php

/%postname%/ users_can_register=0 default_ping_status=closed default_pingback_flag=0 show_avatars=0 timezone_string=UTC blog_public=1 define( 'FORCE_SSL_ADMIN', true ); define( 'DISALLOW_FILE_EDIT', true ); define( 'DISABLE_WP_CRON', true ); define( 'WP_AUTO_UPDATE_CORE', 'minor' ); define( 'FS_METHOD', 'direct' ); define( 'WPMU_PLUGIN_DIR', '/usr/local/lib/sac/wordpress/mu-plugins' );

blog_public=1 means search engines may index the site. While you build the site, use Settings > Reading > Search engine visibility to keep them away.

Everything that makes your site lives in the wordpress database in MariaDB and the uploads under /var/www/wordpress/wp-content/uploads. Plugins and themes you add are under wp-content/plugins and wp-content/themes. Keep /var/www/wp-config.php with your backup, because it holds this site's database password, keys and salts.

Back up the database to a file only root can read. MariaDB's root signs in over the local socket without a password, so no password appears on the command line:

sudo sh -c 'umask 077; mysqldump --single-transaction wordpress > /root/wordpress-$(date +%F).sql'
sudo tar -C /var/www -czf /root/wordpress-files-$(date +%F).tgz wp-config.php wordpress/wp-content

For a whole-instance copy, snapshot the EBS volume.

Port 80 sends browsers to HTTPS, and the health endpoint answers for load balancer checks. XML-RPC, the web cron trigger, the configuration, the installer, the readme, WordPress's own PHP files, a path after index.php, PHP in uploads and dotfiles are not reachable:

H=$(sed -n 's/^set \$wp_host "\(.*\)";$/\1/p' /etc/nginx/wordpress-host.conf)
curl -s -o /dev/null -D - --resolve "$H:80:127.0.0.1" "http://$H/wp-admin/" | tr -d '\r' | awk 'NR==1 {print "port 80:", $2} tolower($1)=="location:" {print "redirects to:", $2}' | sed -E 's#https://[^/]+#https://<your host>#'
curl -sk --resolve "$H:443:127.0.0.1" "https://$H/healthz" for p in /xmlrpc.php /wp-cron.php /wp-config.php /wp-admin/install.php /wp-admin/setup-config.php /readme.html /wp-includes/version.php /index.php/wp-json/wp/v2/users /wp-content/uploads/x.php /.git/config; do
curl -sk -o /dev/null -w "$p: %{http_code}\n" -H 'Sec-Fetch-Site: same-origin' --resolve "$H:443:127.0.0.1" "https://$H$p" done
curl -s -o /dev/null -w 'unknown host name: %{http_code}\n' -H 'Host: example.com' http://127.0.0.1/ || true

port 80: 301 redirects to: https://<your host>/wp-admin/ ok /xmlrpc.php: 403 /wp-cron.php: 403 /wp-config.php: 403 /wp-admin/install.php: 403 /wp-admin/setup-config.php: 403 /readme.html: 403 /wp-includes/version.php: 403 /index.php/wp-json/wp/v2/users: 404 /wp-content/uploads/x.php: 404 /.git/config: 404 unknown host name: 000

000 means nginx closed the connection without an answer. Anonymous visitors cannot list your users, and a form posted from another site is refused:

H=$(sed -n 's/^set \$wp_host "\(.*\)";$/\1/p' /etc/nginx/wordpress-host.conf) for p in /wp-json/wp/v2/users "/?rest_route=/wp/v2/users" "/?author=1" /wp-sitemap-users-1.xml; do curl -sk -o /dev/null -w "$p: %{http_code}\n" --resolve "$H:443:127.0.0.1" "https://$H$p" done curl -sk -o /dev/null -w 'POST /wp-login.php from another site: %{http_code}\n' -H 'Sec-Fetch-Site: cross-site' -d 'log=x&pwd=y' --resolve "$H:443:127.0.0.1" "https://$H/wp-login.php"

/wp-json/wp/v2/users: 401 /?rest_route=/wp/v2/users: 403 /?author=1: 404 /wp-sitemap-users-1.xml: 404 POST /wp-login.php from another site: 403

The credentials file is readable by root only, and wp-config.php by root and the web server. The site files belong to the web server user so that WordPress can update itself, while the must-use plugins belong to root:

sudo stat -c '%a %U:%G %n' /root/wordpress-credentials.txt /var/www/wp-config.php /var/www /var/www/wordpress /var/www/wordpress/wp-content/uploads /var/www/wordpress/index.php /usr/local/lib/sac/wordpress/mu-plugins /usr/local/lib/sac/wordpress/mu-plugins/sac-wp-no-tinymce.php

600 root:root /root/wordpress-credentials.txt 640 root:www-data /var/www/wp-config.php 755 root:root /var/www 750 www-data:www-data /var/www/wordpress 750 www-data:www-data /var/www/wordpress/wp-content/uploads 640 www-data:www-data /var/www/wordpress/index.php 755 root:root /usr/local/lib/sac/wordpress/mu-plugins 644 root:root /usr/local/lib/sac/wordpress/mu-plugins/sac-wp-no-tinymce.php

An uploaded HTML file is sent as a download with nosniff and the sandboxing policy, never rendered as a page of your site:

H=$(sed -n 's/^set \$wp_host "\(.*\)";$/\1/p' /etc/nginx/wordpress-host.conf)
sudo -u www-data install -d -m 0750 /var/www/wordpress/wp-content/uploads/guide-demo echo '<b>demo</b>' | sudo -u www-data tee /var/www/wordpress/wp-content/uploads/guide-demo/demo.html >/dev/null curl -sk -D - -o /dev/null --resolve "$H:443:127.0.0.1" "https://$H/wp-content/uploads/guide-demo/demo.html" | tr -d '\r' | grep -iE '^(HTTP|content-disposition|content-security-policy|x-content-type)'
sudo -u www-data rm -rf /var/www/wordpress/wp-content/uploads/guide-demo

HTTP/2 200 x-content-type-options: nosniff content-security-policy: default-src 'none'; img-src 'self' data:; style-src 'unsafe-inline'; sandbox content-disposition: attachment

WordPress and PHP are blocked from the EC2 instance metadata service, in the web stack and in WP-CLI. A vulnerable plugin therefore cannot fetch the instance's credentials:

for s in nginx php8.3-fpm mariadb wordpress-cron; do printf '%s: %s\n' "$s" "$(systemctl show -p IPAddressDeny --value $s.service)"; done
sudo wp eval '$r = wp_remote_get("http://169.254.169.254/latest/meta-data/", array("timeout" => 4)); echo is_wp_error($r) ? "metadata service: unreachable\n" : "metadata service: REACHABLE\n";'

nginx: 168.63.129.16/32 169.254.169.254/32 fd00:ec2::254/128 php8.3-fpm: 168.63.129.16/32 169.254.169.254/32 fd00:ec2::254/128 mariadb: 168.63.129.16/32 169.254.169.254/32 fd00:ec2::254/128 wordpress-cron: 168.63.129.16/32 169.254.169.254/32 fd00:ec2::254/128 metadata service: unreachable

Automatic updates. WordPress installs minor (6.9.x) releases by itself, normally within 12 hours of their release. The site files belong to the web server user and WP_AUTO_UPDATE_CORE is minor.

To do this, WordPress contacts api.wordpress.org (and downloads.wordpress.org) twice a day. It also checks there for plugin, theme and translation updates, which it shows in Dashboard > Updates and installs only if you turn on their automatic updates. If your instance has no route to the internet, apply updates yourself.

Scheduled jobs. WordPress's scheduled jobs (update checks, publishing scheduled posts, cleanups) run every 5 minutes from wordpress-cron.timer as the web server user, instead of from visitors' page loads. wp-cron.php is not reachable:

systemctl is-enabled wordpress-cron.timer
sudo wp core check-update --minor sudo wp cron event list --fields=hook,recurrence --format=csv | tail -n +2 | sort

enabled Success: WordPress is at the latest version. delete_expired_transients,"1 day" do_pings,Non-repeating recovery_mode_clean_expired_keys,"1 day" wp_delete_temp_updater_backups,"1 week" wp_privacy_delete_old_export_files,"1 hour" wp_scheduled_auto_draft_delete,"1 day" wp_scheduled_delete,"1 day" wp_site_health_scheduled_check,"1 week" wp_update_comment_type_batch,Non-repeating wp_update_plugins,"12 hours" wp_update_themes,"12 hours" wp_update_user_counts,"12 hours" wp_version_check,"12 hours"

Major upgrades. A new major release (such as 7.x) is not installed automatically. Take a snapshot, check that your plugins and theme support it, then use Dashboard > Updates or sudo wp core update. After any upgrade, check that the Classic editor is still off (Step 6).

Plugins and themes. Installing a plugin or theme from the admin area installs code that runs with your site's rights. Install only what you trust and keep it updated. The admin area cannot edit plugin or theme files (DISALLOW_FILE_EDIT).

nginx removes X-Forwarded-For, X-Real-IP, Client-IP, X-Forwarded, Forwarded-For and Forwarded from every request and hands WordPress your configured host name. WordPress therefore sees the address of the connection and never builds links from a host a request claims.

Behind an AWS load balancer, that address is the load balancer's, so the sign-in limit applies to all visitors together. To record visitors' addresses, use nginx's real_ip module with set_real_ip_from set to your load balancer's subnet only. Terminate HTTPS on port 443 of the instance, because WordPress forces HTTPS for the admin area.

Point a DNS record at the instance, then set the name WordPress is served as. This command updates WP_HOME and WP_SITEURL in wp-config.php, rewrites the site address stored in the database and mints a new self-signed certificate for the name. It also updates nginx and the cross-site rules, updates the addresses in /root/wordpress-credentials.txt and keeps the name across reboots:

sudo wordpress-set-hostname <your-domain>

To use a certificate from your own certificate authority instead, copy it over the generated pair and reload nginx. Running wordpress-set-hostname again replaces it with a self-signed one:

sudo install -m 0644 <your-domain>.crt /etc/nginx/ssl/wordpress.crt
sudo install -m 0600 <your-domain>.key /etc/nginx/ssl/wordpress.key
sudo nginx -t && sudo systemctl reload nginx

Once browsers trust the certificate, you can also add an HSTS header (add_header Strict-Transport-Security "max-age=31536000" always;) to /etc/nginx/snippets/sac-wordpress-headers.conf. The image does not send one, because browsers ignore HSTS from a site whose certificate they do not trust.

wordpress-set-password gives the administrator a new random password, signs out every session and records the password in /root/wordpress-credentials.txt. Users change their own password under Users > Profile.

sudo wordpress-set-password

Email. The image has no mail server, so WordPress cannot send password reset, comment or update emails until you add an SMTP plugin you trust (configured with your provider, such as Amazon SES) or a local mail relay.

WP-CLI. Run it as sudo wp <command>. It runs as the web server user www-data in its own sandbox (no metadata service, no shell commands), with the same rights as the site. For example: sudo wp plugin list, sudo wp user list, sudo wp core verify-checksums.

These are the key components and where they live:

• WordPress (owned by www-data, updated by WordPress): /var/www/wordpress
• Configuration (this instance's database password, keys and salts): /var/www/wp-config.php
• Uploads: /var/www/wordpress/wp-content/uploads
• SecureAnyCloud must-use plugins (root owned): /usr/local/lib/sac/wordpress/mu-plugins/
• WP-CLI and its sandboxed wrapper: /usr/local/lib/sac/wordpress/wp-cli.phar, /usr/local/bin/wp
• Database (MariaDB datadir): /var/lib/mysql
• nginx site, request limits, cross-site and TinyMCE rules: /etc/nginx/sites-available/sac-wordpress, /etc/nginx/conf.d/sac-wordpress-guard.conf, /etc/nginx/conf.d/sac-xsite-guard.conf, /etc/nginx/snippets/sac-wordpress-*.conf, /etc/nginx/snippets/sac-wp-no-tinymce.conf
• PHP settings: /etc/php/8.3/fpm/conf.d/99-sac-wordpress.ini, /etc/php/8.3/cli/conf.d/99-sac-wordpress.ini
• MariaDB settings: /etc/mysql/mariadb.conf.d/99-sac-wordpress.cnf
• Scheduled jobs: wordpress-cron.timer, wordpress-cron.service
• Certificate and key: /etc/nginx/ssl/
• First boot and helpers: /usr/local/sbin/wordpress-firstboot.sh, wordpress-set-hostname, wordpress-set-password, wordpress-cred-roundtrip
• Licence, release and image notes: /usr/share/doc/sac-wordpress/
• Credentials: /root/wordpress-credentials.txt (mode 0600)

• Allow port 22 in the security group from your own networks only.
• Change the administrator email to your own (Step 4), keep its password secret and rotate it if it may have been shared (Step 13). Give editors and authors their own accounts with the narrowest role that works.
• Keep wp-config.php and your database backups secret (Step 8).
• Use your own DNS name and a certificate your browsers trust (Step 12).
• Leave automatic minor updates on, keep plugins and themes updated, and install only plugins and themes you trust. Keep the Classic editor off, because re-enabling it brings back TinyMCE 4.9.11 and its unfixed advisories (Step 6).
• Keep the operating system patched. Unattended security upgrades are on, and sudo apt-get update && sudo apt-get upgrade applies everything else. MariaDB, PHP-FPM and PHP's zip extension come from Ubuntu's universe repository. sudo pro security-status --esm-apps shows whether Ubuntu Pro (ESM Apps) has security updates for them (none were pending when the image was built).