LW Firewall

Lightweight WordPress firewall — rate-limits endpoints, blocks bots, bans repeat offenders, and adds security headers.

The Problem

Bots brute-force wp-login.php, flood wp-cron.php and xmlrpc.php, crawl WooCommerce filter combinations, scan for vulnerabilities via 404s, and abuse the REST API — all generating thousands of uncacheable requests that overload your server.

How It Works

LW Firewall installs an MU-plugin worker that intercepts requests before WordPress fully loads. The processing order:

1. IP Whitelist — whitelisted IPs skip all checks
2. IP Blacklist — blacklisted IPs get 403 immediately
3. Geo Blocking — block entire countries (Cloudflare header or CIDR lookup)
4. Auto-Ban — previously banned IPs get 403
5. 404 Flood — IPs with excessive 404s get 429
6. Bot Blocking — User-Agent matching (all requests)
7. Endpoint Detection — filter params, cron, xmlrpc, login, REST API
8. Rate Limiting — per-IP counters with auto-ban escalation

That list is the worker's pre-WordPress path. Registration spam protection, password-reset flood protection and the administrator alerts run inside WordPress instead, because they need the user API — but they share the same storage backend and ban store, so an IP banned by any of them is blocked by the worker on its next request.

Features

Endpoint Protection

Endpoint	Protection	Response
WooCommerce filters	Rate limit + bot blocking	302 redirect or 429
wp-login.php	Brute-force rate limiting	429
wp-cron.php	DDoS rate limiting	429
xmlrpc.php	DDoS/brute-force rate limiting	429
REST API (/wp-json/)	Rate limiting	429
404 flood	Vulnerability scanner blocking	429

Bot Blocking

• Block requests by User-Agent substring matching (case-insensitive)
• 20+ known bad bots blocked by default (AhrefsBot, SemrushBot, DotBot, GPTBot, etc.)
• Add/remove bot patterns via admin UI or WP-CLI

IP Whitelist / Blacklist

• Manual IP allow/block lists
• Supports individual IPs and CIDR ranges (e.g. 192.168.1.0/24)
• Whitelisted IPs bypass all firewall checks
• Blacklisted IPs are always blocked with 403

Geo Blocking

• Block visitors from specific countries by ISO 3166-1 alpha-2 code (e.g. CN, RU, IN)
• Cloudflare — uses CF-IPCountry header (instant, zero-cost)
• Without Cloudflare — CIDR-based lookup from local cache (weekly auto-update from ipdeny.com)
• Fail-open: if no cache exists and no CF header is present, the request is not blocked
• Configurable action: 403 Forbidden or redirect to homepage
• Manual CIDR cache update via admin UI or WP-CLI

Auto-Ban

• Automatically bans IPs that repeatedly exceed rate limits
• Configurable threshold (default: 3 violations)
• Configurable ban duration (default: 1 hour)
• Escalating protection — casual users won't trigger it, persistent attackers get banned
• Bans are listable and liftable from the IP Rules tab or WP-CLI, and record why they happened (failed logins, registration spam, password-reset flood, rate limit)
• Lifting a ban clears the counters behind it, so the address is not re-banned on its next request

Brute-Force Login Lockout

Counts failed logins per IP and bans the address once the threshold is reached inside the window. Off by default — enable it with login_limit_enabled.

Setting	Default	Meaning
login_max_attempts	5	Failures before the ban
login_lockout_window	600	Seconds the failures are counted over
login_lockout_duration	3600	How long the ban lasts

The ban is written to the shared ban store, so the MU-plugin worker blocks the address site-wide on its next request, not just on the login form. Whitelisted IPs are checked first and bypass it entirely.

Registration Spam Protection

Blocks bot sign-ups on wp-login.php?action=register without a captcha:

• Signed proof-of-render token — a direct POST that never loaded the form is rejected
• Hidden honeypot field, invisible to real users
• Minimum fill time, so instant bot submissions are refused
• Single-use tokens, so one rendered form can register only once
• Auto-ban for IPs that repeatedly submit spam registrations

Password Reset Flood Protection

Hooked on lostpassword_post — the one chokepoint both WordPress core and WooCommerce's own my-account form pass through, so wp-login.php?action=lostpassword and the WooCommerce "Lost your password?" form are covered by the same rules.

A reset flood has three shapes, so there are three independent limits:

Limit	Default	What it stops
Per IP	5 / 15 min	One host hammering the form
Per target account	3 / hour	Many hosts flooding one person's inbox — per-IP limiting cannot see this
Site-wide	30 / hour	Total reset emails per hour; protects your mail quota and your domain's sending reputation

The per-account counter is keyed by user ID, so admin, Admin and the account's email address share one bucket. Once an IP is over its own limit the request is refused without touching the target counter, so an attacker cannot use their own flood to lock the victim out of a genuine reset.

Also included:

• Proof-of-render token and honeypot on the wp-login form, with its own fill time, lifetime and single-use settings (enforced only there — other lost-password forms never render the token; the rate limits apply everywhere)
• Optional auto-ban for IPs that trip the per-IP limit or fail the token check. Account and site-wide limits never ban — they say nothing about who happened to ask last
• Optional hardening that takes administrator accounts out of the reset flow entirely
• Optional email alert when a limit is reached, throttled to one message per limit per hour
• Requests started by a user with edit_users or by WP-CLI bypass every check, so the Users screen "Send password reset link" keeps working during a flood

New Administrator Alerts

Email notification whenever an account gains administrator privileges, or an existing administrator account is modified — no matter how it happened. Two detection paths, because neither is complete alone:

Path	Catches	Latency
Core hooks	Anything going through the WordPress user API — admin screens, plugins, REST, WP-CLI. Reports the acting user and their IP	Immediate
Hourly reconciliation scan	A direct database write, code bypassing the user API, or changes made while the plugin was inactive	Within the hour

The stored snapshot fingerprints each administrator (user ID, username, email address, and a digest of the stored password hash), so a takeover is caught too: rewriting an admin's email address hands the attacker the password reset flow while the user ID stays the same, which an ID-only comparison would never see. The digest only answers "did this change?" — no password or usable hash is stored, and none is ever printed in an alert.

Both paths write to the same snapshot, so one event produces one alert. Existing administrators are recorded silently when the feature is enabled, so upgrading sites are never mailed about accounts they already had.

Security Headers

One-click addition of security HTTP headers:

• X-Content-Type-Options: nosniff
• X-Frame-Options: SAMEORIGIN
• Referrer-Policy: strict-origin-when-cross-origin
• Permissions-Policy: camera=(), microphone=(), geolocation=()

Storage Backends

Backend	Speed	Persistence	Requirement
APCu	Fastest	Per-process	apcu extension
Redis	Fast	Shared	redis extension + server
File	Fallback	Disk-based	Always available

Auto-detection picks the best available backend.

MU-Plugin Worker

• Loads on muplugins_loaded (priority 1) — before themes and plugins
• Own autoloader — zero dependency on WordPress plugin system
• Automatic install on activation, removal on deactivation
• Auto-update — worker file is automatically replaced when its version doesn't match the plugin version

Cloudflare Support

• Automatic real IP detection via CF-Connecting-IP header
• Cloudflare IP range validation to prevent header spoofing
• The CF-IPCountry header used for geo blocking clears the same trust test

Reverse Proxy Support

Behind a proxy or load balancer every request arrives with the proxy's address, so without configuration the whole internet shares one rate-limit bucket, one ban and one country. On the common "nginx in front of Apache on the same host" layout that address is 127.0.0.1.

List your own proxies under IP Rules → Reverse Proxy. The forwarded chain is then read right to left, skipping hops that are themselves trusted, and the first address you do not vouch for is the client.

This is opt-in on purpose: a forwarded header is written by the client until the hop that set it is known, so trusting one by default would let any visitor pick their own IP. The Status tab warns when the address the firewall sees is not routable on the internet.

Request Logging

• Optional logging of all blocked requests (time, IP, reason, User-Agent, URL)
• Admin log viewer with table display
• One-click log clearing

Installation

Via Composer:

composer require lwplugins/lw-firewall

Manual:

1. Download the latest release ZIP
2. Upload to /wp-content/plugins/
3. Activate in WordPress admin

Settings

Navigate to LW Plugins > Firewall in the admin panel.

Tab	Description
General	Enable/disable, storage backend, rate limit, time window, action, filter params
Protection	Endpoint toggles (cron, xmlrpc, login, REST API, 404) and auto-ban settings
Bots	Manage blocked bot User-Agent patterns
IP Rules	IP whitelist and blacklist (IPs and CIDR ranges), trusted reverse proxies, plus the automatic-ban table with per-row unblock
Spam	Registration spam protection and password-reset flood protection
Geo Blocking	Country-based blocking with Cloudflare or CIDR fallback
Security	HTTP security headers toggle
Alerts	New-administrator and account-takeover email alerts, recipients, scan schedule
Status	MU-plugin worker status, worker version, active storage backend, reinstall worker
Logs	Enable logging, view blocked requests, clear log
Import / Export	Export settings as JSON, import on another site

WP-CLI Commands

All 31 commands are listed below. --format accepts table (default), json, csv or yaml.

Status

wp lw-firewall status

Configuration

config reads and writes whole values; config-items edits a single entry of a list setting without resending the whole list.

wp lw-firewall config list [--format=<format>]
wp lw-firewall config get <key> [--format=<format>]
wp lw-firewall config set <key> <value>
wp lw-firewall config reset [--yes]

wp lw-firewall config-items add <key> <entry>
wp lw-firewall config-items remove <key> <entry>

# Examples
wp lw-firewall config set rate_limit 50
wp lw-firewall config set storage redis
wp lw-firewall config set protect_login true
wp lw-firewall config set filter_params "filter_|30,add-to-cart|10"
wp lw-firewall config-items add blocked_countries KP
wp lw-firewall config-items remove ip_blacklist 203.0.113.42

Bots

wp lw-firewall bots list [--format=<format>]
wp lw-firewall bots add <user_agent>
wp lw-firewall bots remove <user_agent>

IP whitelist / blacklist

wp lw-firewall ip list <whitelist|blacklist> [--format=<format>]
wp lw-firewall ip add <whitelist|blacklist> <ip>
wp lw-firewall ip remove <whitelist|blacklist> <ip>

# Examples
wp lw-firewall ip add whitelist 192.168.1.100
wp lw-firewall ip add blacklist 10.0.0.0/8

Geo blocking

wp lw-firewall geo list [--format=<format>]
wp lw-firewall geo add <code>
wp lw-firewall geo remove <code>
wp lw-firewall geo update          # refresh the cached CIDR lists now

New-administrator alerts

wp lw-firewall alerts status [--format=<format>]
wp lw-firewall alerts scan                  # run the reconciliation scan now
wp lw-firewall alerts test                  # send a test alert to the recipients
wp lw-firewall alerts baseline              # show the known-administrator snapshot
wp lw-firewall alerts baseline --reset      # re-take the snapshot from the live list

alerts scan also lets sites with WP-Cron disabled drive the scan from a system cron.

Password reset flood protection

wp lw-firewall reset status [--format=<format>]   # settings plus the option key behind each
wp lw-firewall reset on [--proof] [--auto-ban] [--alert] [--block-admins]
wp lw-firewall reset off                          # limits are kept, so `on` restores them

Flag	Effect
--proof	Require the proof-of-render token on the wp-login form
--auto-ban	Ban IPs that trip the per-IP limit or fail the token check
--alert	Email the Alerts-tab recipients when a limit is reached
--block-admins	Refuse password resets for administrator accounts entirely — recovery then needs WP-CLI or another administrator

Automatic bans

wp lw-firewall ban list [--format=<format>]   # who is banned, why, until when
wp lw-firewall ban check <ip>                 # is this address banned?
wp lw-firewall ban remove <ip>                # lift one ban
wp lw-firewall ban clear [--yes]              # lift every tracked ban

ban remove also clears the counters that produced the ban — rate-limit, failed-login, registration, password-reset and 404 — so the address starts from zero instead of being re-banned on its next request. The active column in ban list reconciles the index against the storage backend: no means the entry is tracked but no longer enforced, which happens after a Redis flush or an APCu restart.

The same table, with an Unblock button per row, is on the IP Rules settings tab.

Logs

wp lw-firewall logs list [--limit=<n>] [--format=<format>]
wp lw-firewall logs clear [--yes]

MU-plugin worker

wp lw-firewall worker install
wp lw-firewall worker remove

wp-config.php Overrides

Every setting can be overridden by a constant named LW_FIREWALL_ + the option key in uppercase. A constant always wins over the admin UI and WP-CLI, and the settings screen lists the options a constant has pinned so a locked field is visibly locked.

Before 1.5.5 the constants applied to single option reads but not to the worker, the runtime hooks or the .htaccess sync. Upgrade if you rely on them.

// Reverse proxy — leave unset unless the site is behind one. Cloudflare is
// detected automatically and needs nothing here.
define( 'LW_FIREWALL_TRUSTED_PROXIES', [ '127.0.0.1' ] );
define( 'LW_FIREWALL_PROXY_HEADER', 'x-forwarded-for' );  // or x-real-ip, forwarded

// Core
define( 'LW_FIREWALL_ENABLED', true );
define( 'LW_FIREWALL_STORAGE', 'apcu' );                 // auto, apcu, redis, file
define( 'LW_FIREWALL_RATE_LIMIT', 30 );
define( 'LW_FIREWALL_RATE_WINDOW', 60 );                 // seconds
define( 'LW_FIREWALL_ACTION', '429' );                   // 429 or redirect
define( 'LW_FIREWALL_LOG_ENABLED', false );

// Endpoint protection
define( 'LW_FIREWALL_PROTECT_CRON', true );
define( 'LW_FIREWALL_PROTECT_XMLRPC', true );
define( 'LW_FIREWALL_PROTECT_LOGIN', true );
define( 'LW_FIREWALL_PROTECT_REST_API', false );
define( 'LW_FIREWALL_PROTECT_404', false );

// Auto-ban
define( 'LW_FIREWALL_AUTO_BAN_ENABLED', true );
define( 'LW_FIREWALL_AUTO_BAN_THRESHOLD', 3 );
define( 'LW_FIREWALL_AUTO_BAN_DURATION', 3600 );         // seconds

// Brute-force login lockout
define( 'LW_FIREWALL_LOGIN_LIMIT_ENABLED', false );
define( 'LW_FIREWALL_LOGIN_MAX_ATTEMPTS', 5 );
define( 'LW_FIREWALL_LOGIN_LOCKOUT_WINDOW', 600 );       // seconds
define( 'LW_FIREWALL_LOGIN_LOCKOUT_DURATION', 3600 );    // seconds

// Registration spam protection
define( 'LW_FIREWALL_REGISTER_PROTECT_ENABLED', true );
define( 'LW_FIREWALL_REGISTER_HONEYPOT', true );
define( 'LW_FIREWALL_REGISTER_SINGLE_USE', true );
define( 'LW_FIREWALL_REGISTER_MIN_FILL_TIME', 2 );       // seconds
define( 'LW_FIREWALL_REGISTER_TOKEN_MAX_AGE', 3600 );    // seconds
define( 'LW_FIREWALL_REGISTER_BAN_THRESHOLD', 3 );
define( 'LW_FIREWALL_REGISTER_BAN_DURATION', 3600 );     // seconds

// Password reset flood protection
define( 'LW_FIREWALL_RESET_PROTECT_ENABLED', true );
define( 'LW_FIREWALL_RESET_IP_MAX', 5 );                 // 0 disables this axis
define( 'LW_FIREWALL_RESET_IP_WINDOW', 900 );            // seconds
define( 'LW_FIREWALL_RESET_USER_MAX', 3 );               // 0 disables this axis
define( 'LW_FIREWALL_RESET_USER_WINDOW', 3600 );         // seconds
define( 'LW_FIREWALL_RESET_GLOBAL_MAX', 30 );            // per hour, 0 disables
define( 'LW_FIREWALL_RESET_PROOF_ENABLED', true );
define( 'LW_FIREWALL_RESET_MIN_FILL_TIME', 2 );          // seconds
define( 'LW_FIREWALL_RESET_TOKEN_MAX_AGE', 3600 );       // seconds
define( 'LW_FIREWALL_RESET_SINGLE_USE', true );
define( 'LW_FIREWALL_RESET_AUTO_BAN', false );
define( 'LW_FIREWALL_RESET_BAN_DURATION', 3600 );        // seconds
define( 'LW_FIREWALL_RESET_BLOCK_ADMINS', false );
define( 'LW_FIREWALL_RESET_ALERT_ENABLED', false );

// New-administrator alerts
define( 'LW_FIREWALL_ADMIN_ALERT_ENABLED', false );
define( 'LW_FIREWALL_ADMIN_ALERT_EMAIL', 'security@example.com' );  // empty = site admin email
define( 'LW_FIREWALL_ADMIN_ALERT_SCAN_ENABLED', true );
define( 'LW_FIREWALL_ADMIN_ALERT_CHANGES', true );

// Security headers and geo blocking
define( 'LW_FIREWALL_SECURITY_HEADERS', true );
define( 'LW_FIREWALL_GEO_ENABLED', true );

// Emergency kill-switch for the MU-plugin worker
define( 'LW_FIREWALL_DISABLE_WORKER', true );

The list settings (ip_whitelist, ip_blacklist, blocked_bots, filter_params, blocked_countries) accept constants too, as arrays — but they are usually easier to manage with wp lw-firewall config-items or the admin UI:

define( 'LW_FIREWALL_IP_WHITELIST', [ '192.168.1.100', '10.0.0.0/8' ] );

Requirements

• PHP 8.2 or higher
• WordPress 6.0 or higher

Part of LW Plugins

LW Firewall is part of the LW Plugins family — lightweight WordPress plugins with minimal footprint and maximum impact.

Plugin	Description
LW SEO	Essential SEO features without the bloat
LW Disable	Disable WordPress features
LW Enable	Enable WordPress features like SVG uploads
LW ZenAdmin	Clean up your admin — notices sidebar & widget manager
LW Firewall	Lightweight firewall — rate limiting, bot blocking, auto-ban
LW Cookie	GDPR-compliant cookie consent
LW LMS	Lightweight LMS — courses, lessons, progress tracking
LW Translate	Manage community translations from GitHub
LW Site Manager	Site maintenance via AI/REST using Abilities API

License

GPL-2.0-or-later. See LICENSE for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Sponsor

Supported by Sinann