diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..6674ac2
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,15 @@
+# Kopieer naar .env en pas de waarden aan. .env wordt niet gecommit (zie .gitignore).
+
+TYPE=docker
+QRCODE_GENERATOR=internal-chillerlan.qrcode
+BASE_URL=http://localhost
+
+DATABASE_HOST=php-dynamic-qrcode-db
+DATABASE_PORT=3306
+DATABASE_NAME=qrcode
+DATABASE_USER=qrcode
+DATABASE_PASSWORD=change-me-to-a-strong-password
+DATABASE_PREFIX=
+DATABASE_CHARSET=utf8
+
+MYSQL_ROOT_PASSWORD=change-me-to-a-strong-root-password
diff --git a/.gitignore b/.gitignore
index e00e331..e56fac6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 .settings
 .project
 .idea
-.DS_Store
\ No newline at end of file
+.DS_Store
+.env
\ No newline at end of file
diff --git a/Dockerfile b/Dockerfile
index 5668259..3e07eeb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -86,7 +86,10 @@ RUN docker-php-ext-install sockets && docker-php-ext-enable sockets
 
 RUN mkdir -p /opt && chmod 777 /opt
 WORKDIR /opt
-RUN git clone https://github.com/chillerlan/php-qrcode.git \
+# Vastgezet op 5.0.5 (laatste 5.x-release): vanaf 6.0.0 vereist de library PHP >= 8.4,
+# terwijl deze image op PHP 8.3 draait. Een ongepinde clone van master is bovendien
+# een reproduceerbaarheids-/supply-chain-risico (build kan zonder waarschuwing breken).
+RUN git clone --branch 5.0.5 --depth 1 https://github.com/chillerlan/php-qrcode.git \
         && chmod -R 777 ./php-qrcode
 RUN cp ./php-qrcode/composer.json /var/www/html/composer.json
 RUN mkdir -p /var/www/html/test && chmod 777 /var/www/html/test
diff --git a/Dockerfile.fpm b/Dockerfile.fpm
new file mode 100644
index 0000000..01c9edc
--- /dev/null
+++ b/Dockerfile.fpm
@@ -0,0 +1,59 @@
+FROM php:8.3-fpm
+
+RUN if [ "$(grep '^VERSION_ID=' /etc/os-release | cut -d '=' -f 2 | tr -d '"')" -eq "9" ]; then \
+        sed -i -e 's/deb.debian.org/archive.debian.org/g' \
+               -e 's/security.debian.org/archive.debian.org/g' \
+               -e '/stretch-updates/d' /etc/apt/sources.list; \
+    fi
+
+ADD https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions /usr/local/bin/
+
+RUN chmod +x /usr/local/bin/install-php-extensions
+
+RUN DEBIAN_FRONTEND=noninteractive apt-get update -q \
+    && DEBIAN_FRONTEND=noninteractive apt-get install -qq -y \
+      curl \
+      libzip-dev \
+      libjpeg62-turbo-dev \
+      libpng-dev \
+      libfreetype6-dev \
+      zip unzip \
+    && install-php-extensions \
+      gd \
+      gettext \
+      intl \
+      mysqli \
+      opcache \
+      pdo_mysql \
+      sockets \
+      zip
+
+# Install Composer.
+ENV PATH=$PATH:/root/composer/vendor/bin \
+  COMPOSER_ALLOW_SUPERUSER=1 \
+  COMPOSER_HOME=/root/composer
+RUN cd /opt \
+  && curl -sSL https://getcomposer.org/installer > composer-setup.php \
+  && curl -sSL https://composer.github.io/installer.sha384sum > composer-setup.sha384sum \
+  && sha384sum --check composer-setup.sha384sum \
+  && php composer-setup.php --install-dir=/usr/local/bin --filename=composer --2 \
+  && rm /opt/composer-setup.php /opt/composer-setup.sha384sum
+
+RUN mkdir -p /opt && chmod 777 /opt
+WORKDIR /opt
+# Zie Dockerfile: vastgezet op 5.0.5, want 6.0.0+ vereist PHP >= 8.4.
+RUN git clone --branch 5.0.5 --depth 1 https://github.com/chillerlan/php-qrcode.git \
+        && chmod -R 777 ./php-qrcode
+RUN cp ./php-qrcode/composer.json /var/www/html/composer.json
+RUN cp -R ./php-qrcode/src /var/www/html/
+
+WORKDIR /var/www/html
+RUN composer update
+COPY ./src ./
+RUN chown -R www-data:www-data /var/www/html \
+    && find /var/www/html -type f -exec chmod 644 {} \; \
+    && find /var/www/html -type d -exec chmod 755 {} \; \
+    && chmod -R 775 /var/www/html/saved_qrcode
+
+EXPOSE 9000
+CMD ["php-fpm"]
diff --git a/db/init.sql b/db/init.sql
new file mode 100644
index 0000000..4f5d28b
--- /dev/null
+++ b/db/init.sql
@@ -0,0 +1,91 @@
+SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO";
+SET time_zone = "+00:00";
+
+/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
+/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
+/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
+/*!40101 SET NAMES utf8 */;
+
+CREATE TABLE IF NOT EXISTS `users` (
+  `id` int(25) NOT NULL AUTO_INCREMENT,
+  `username` varchar(50) NOT NULL,
+  `password` varchar(255) NOT NULL,
+  `series_id` varchar(60) DEFAULT NULL,
+  `remember_token` varchar(255) DEFAULT NULL,
+  `expires` datetime DEFAULT NULL,
+  `type` varchar(10) NOT NULL,
+  `must_change_password` tinyint(1) NOT NULL DEFAULT 0,
+  `password_changed_at` datetime DEFAULT NULL,
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `username` (`username`)
+) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=0 ;
+
+-- Default super admin account. Credentials: superadmin / superadmin
+-- must_change_password=1 forces a password change on first login (see Fase 1 hardening).
+INSERT INTO `users` (`id`, `username`, `password`, `series_id`, `remember_token`, `expires`, `type`, `must_change_password`, `password_changed_at`) VALUES
+(1, 'superadmin', '$2y$10$xpZc5KC.aU2XHkcqhuZGFuAnqmtL4Unt8MysOyylceq.19XIyoZpG', NULL, NULL, NULL, 'super', 1, NULL);
+
+CREATE TABLE IF NOT EXISTS `dynamic_qrcodes` (
+  `id` int(10) NOT NULL AUTO_INCREMENT,
+  `id_owner` int(25) NULL DEFAULT NULL,
+  `filename` varchar(45) NOT NULL,
+  `format` varchar(45) DEFAULT NULL,
+  `identifier` longtext,
+  `link` varchar(500) DEFAULT NULL,
+  `qrcode` varchar(60) DEFAULT NULL,
+  `scan` int(11) NOT NULL DEFAULT '0',
+  `state` varchar(20) NOT NULL DEFAULT 'enable',
+  `created_by` int(10) unsigned NOT NULL DEFAULT '0',
+  `created_at` timestamp NULL DEFAULT NULL,
+  `updated_by` int(10) unsigned NOT NULL DEFAULT '0',
+  `updated_at` timestamp NULL DEFAULT NULL,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=0 ;
+
+CREATE TABLE IF NOT EXISTS `static_qrcodes` (
+  `id` int(10) NOT NULL AUTO_INCREMENT,
+  `id_owner` int(25) NULL DEFAULT NULL,
+  `filename` varchar(45) CHARACTER SET utf8 NOT NULL,
+  `format` varchar(45) DEFAULT NULL,
+  `type` varchar(45) CHARACTER SET utf8 DEFAULT NULL,
+  `content` mediumtext CHARACTER SET utf8,
+  `qrcode` varchar(60) CHARACTER SET utf8 DEFAULT NULL,
+  `state` varchar(20) CHARACTER SET utf8 NOT NULL DEFAULT 'enable',
+  `created_by` int(10) unsigned NOT NULL DEFAULT '0',
+  `created_at` timestamp NULL DEFAULT NULL,
+  `updated_by` int(10) unsigned NOT NULL DEFAULT '0',
+  `updated_at` timestamp NULL DEFAULT NULL,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=0 ;
+
+-- Security hardening (Fase 1): rate limiting op login pogingen
+CREATE TABLE IF NOT EXISTS `login_attempts` (
+  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
+  `username` varchar(50) NOT NULL,
+  `ip_address` varchar(45) NOT NULL,
+  `success` tinyint(1) NOT NULL DEFAULT 0,
+  `attempted_at` datetime NOT NULL,
+  PRIMARY KEY (`id`),
+  KEY `username_attempted_at` (`username`, `attempted_at`),
+  KEY `ip_attempted_at` (`ip_address`, `attempted_at`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+
+-- Security hardening (Fase 1): audit log van gevoelige acties
+CREATE TABLE IF NOT EXISTS `audit_log` (
+  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  `user_id` int(25) DEFAULT NULL,
+  `username` varchar(50) DEFAULT NULL,
+  `action` varchar(50) NOT NULL,
+  `target_type` varchar(30) DEFAULT NULL,
+  `target_id` varchar(50) DEFAULT NULL,
+  `ip_address` varchar(45) DEFAULT NULL,
+  `user_agent` varchar(255) DEFAULT NULL,
+  `created_at` datetime NOT NULL,
+  PRIMARY KEY (`id`),
+  KEY `created_at` (`created_at`),
+  KEY `user_id` (`user_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+
+/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
+/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
+/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
diff --git a/db/migrations/002_security_hardening.sql b/db/migrations/002_security_hardening.sql
new file mode 100644
index 0000000..edb5099
--- /dev/null
+++ b/db/migrations/002_security_hardening.sql
@@ -0,0 +1,57 @@
+-- Fase 1 security hardening migratie.
+-- Voer uit tegen een bestaande database (gebruikt de originele
+-- giandonatoinverso/php-dynamic-qr-code-db image of een oudere init.sql).
+-- Kolommen/tabellen worden alleen toegevoegd als ze nog niet bestaan.
+
+SET @db := DATABASE();
+
+SET @col_exists := (
+  SELECT COUNT(*) FROM information_schema.COLUMNS
+  WHERE TABLE_SCHEMA = @db AND TABLE_NAME = 'users' AND COLUMN_NAME = 'must_change_password'
+);
+SET @sql := IF(@col_exists = 0,
+  'ALTER TABLE `users` ADD COLUMN `must_change_password` TINYINT(1) NOT NULL DEFAULT 0',
+  'SELECT 1');
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @col_exists := (
+  SELECT COUNT(*) FROM information_schema.COLUMNS
+  WHERE TABLE_SCHEMA = @db AND TABLE_NAME = 'users' AND COLUMN_NAME = 'password_changed_at'
+);
+SET @sql := IF(@col_exists = 0,
+  'ALTER TABLE `users` ADD COLUMN `password_changed_at` DATETIME DEFAULT NULL',
+  'SELECT 1');
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+-- Bestaand superadmin account met het fabriekswachtwoord (superadmin/superadmin)
+-- moet bij eerstvolgende login het wachtwoord wijzigen.
+UPDATE `users`
+SET `must_change_password` = 1
+WHERE `username` = 'superadmin'
+  AND `password` = '$2y$10$xpZc5KC.aU2XHkcqhuZGFuAnqmtL4Unt8MysOyylceq.19XIyoZpG';
+
+CREATE TABLE IF NOT EXISTS `login_attempts` (
+  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
+  `username` varchar(50) NOT NULL,
+  `ip_address` varchar(45) NOT NULL,
+  `success` tinyint(1) NOT NULL DEFAULT 0,
+  `attempted_at` datetime NOT NULL,
+  PRIMARY KEY (`id`),
+  KEY `username_attempted_at` (`username`, `attempted_at`),
+  KEY `ip_attempted_at` (`ip_address`, `attempted_at`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+
+CREATE TABLE IF NOT EXISTS `audit_log` (
+  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  `user_id` int(25) DEFAULT NULL,
+  `username` varchar(50) DEFAULT NULL,
+  `action` varchar(50) NOT NULL,
+  `target_type` varchar(30) DEFAULT NULL,
+  `target_id` varchar(50) DEFAULT NULL,
+  `ip_address` varchar(45) DEFAULT NULL,
+  `user_agent` varchar(255) DEFAULT NULL,
+  `created_at` datetime NOT NULL,
+  PRIMARY KEY (`id`),
+  KEY `created_at` (`created_at`),
+  KEY `user_id` (`user_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
diff --git a/docker-compose.prod.yml b/docker-compose.prod.yml
new file mode 100644
index 0000000..fec6531
--- /dev/null
+++ b/docker-compose.prod.yml
@@ -0,0 +1,66 @@
+services:
+  nginx:
+    image: "nginx:1.27-alpine"
+    restart: "unless-stopped"
+    ports:
+      - "80:80"
+      # 443 pas openzetten zodra SSL-certificaten zijn gemount (bv. via certbot-volume
+      # of een losse reverse proxy zoals Caddy/Traefik ervoor). Zie infra-fase van het plan.
+    volumes:
+      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
+      - php_dynamic_qrcode_saved_qrcode_data:/var/www/html/saved_qrcode:ro
+    depends_on:
+      - php-dynamic-qrcode
+    networks:
+      - php-dynamic-qrcode-network
+
+  php-dynamic-qrcode:
+    build:
+      context: .
+      dockerfile: Dockerfile.fpm
+    restart: "unless-stopped"
+    environment:
+      TYPE: "docker"
+      QRCODE_GENERATOR: "${QRCODE_GENERATOR:-internal-chillerlan.qrcode}"
+      BASE_URL: "${BASE_URL:?zet BASE_URL in .env, bv. https://qr.ensembia.com}"
+      DATABASE_HOST: "php-dynamic-qrcode-db"
+      DATABASE_PORT: "3306"
+      DATABASE_NAME: "${DATABASE_NAME:-qrcode}"
+      DATABASE_USER: "${DATABASE_USER:-qrcode}"
+      DATABASE_PASSWORD: "${DATABASE_PASSWORD:?zet DATABASE_PASSWORD in .env}"
+      DATABASE_PREFIX: "${DATABASE_PREFIX:-}"
+      DATABASE_CHARSET: "${DATABASE_CHARSET:-utf8}"
+    depends_on:
+      php-dynamic-qrcode-db:
+        condition: service_healthy
+    volumes:
+      - php_dynamic_qrcode_saved_qrcode_data:/var/www/html/saved_qrcode
+    networks:
+      - php-dynamic-qrcode-network
+
+  php-dynamic-qrcode-db:
+    image: "mysql:8.0"
+    restart: "unless-stopped"
+    volumes:
+      - php_dynamic_qrcode_db_data:/var/lib/mysql
+      - ./db/init.sql:/docker-entrypoint-initdb.d/init.sql:ro
+    environment:
+      MYSQL_ROOT_PASSWORD: "${MYSQL_ROOT_PASSWORD:?zet MYSQL_ROOT_PASSWORD in .env}"
+      MYSQL_DATABASE: "${DATABASE_NAME:-qrcode}"
+      MYSQL_USER: "${DATABASE_USER:-qrcode}"
+      MYSQL_PASSWORD: "${DATABASE_PASSWORD:?zet DATABASE_PASSWORD in .env}"
+    healthcheck:
+      test: ["CMD", "mysqladmin", "ping", "-h", "localhost", "-u", "root", "-p${MYSQL_ROOT_PASSWORD}"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+    networks:
+      - php-dynamic-qrcode-network
+
+volumes:
+  php_dynamic_qrcode_db_data:
+  php_dynamic_qrcode_saved_qrcode_data:
+
+networks:
+  php-dynamic-qrcode-network:
+    driver: bridge
diff --git a/docker-compose.yml b/docker-compose.yml
index ba133c5..fc1cdbd 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,48 +1,53 @@
-version: "3.2"
 services:
   php-dynamic-qrcode:
-    image: "giandonatoinverso/php-dynamic-qr-code:latest"
+    build:
+      context: .
+      dockerfile: Dockerfile
     restart: "unless-stopped"
     environment:
-      TYPE: "docker"
-      QRCODE_GENERATOR: "internal-chillerlan.qrcode"
-      BASE_URL: "https://mydomain.com"
+      TYPE: "${TYPE:-docker}"
+      QRCODE_GENERATOR: "${QRCODE_GENERATOR:-internal-chillerlan.qrcode}"
+      BASE_URL: "${BASE_URL:-http://localhost}"
       DATABASE_HOST: "php-dynamic-qrcode-db"
       DATABASE_PORT: "3306"
-      DATABASE_NAME: "qrcode"
-      DATABASE_USER: "qrcode"
-      DATABASE_PASSWORD: "changeme"
-      DATABASE_PREFIX: ""
-      DATABASE_CHARSET: "utf8"
+      DATABASE_NAME: "${DATABASE_NAME:-qrcode}"
+      DATABASE_USER: "${DATABASE_USER:-qrcode}"
+      DATABASE_PASSWORD: "${DATABASE_PASSWORD:?zet DATABASE_PASSWORD in .env}"
+      DATABASE_PREFIX: "${DATABASE_PREFIX:-}"
+      DATABASE_CHARSET: "${DATABASE_CHARSET:-utf8}"
     ports:
-      - 80:80
+      - "80:80"
     depends_on:
-      - php-dynamic-qrcode-db
+      php-dynamic-qrcode-db:
+        condition: service_healthy
     volumes:
       - php_dynamic_qrcode_saved_qrcode_data:/var/www/html/saved_qrcode
     networks:
       - php-dynamic-qrcode-network
 
   php-dynamic-qrcode-db:
-    image: "giandonatoinverso/php-dynamic-qr-code-db:latest"
+    image: "mysql:8.0"
     restart: "unless-stopped"
     volumes:
       - php_dynamic_qrcode_db_data:/var/lib/mysql
-    ports:
-      - '13306:3306'
+      - ./db/init.sql:/docker-entrypoint-initdb.d/init.sql:ro
     environment:
-      MYSQL_ROOT_PASSWORD: "changeme"
-      MYSQL_DATABASE: "qrcode"
-      MYSQL_USER: "qrcode"
-      MYSQL_PASSWORD: "changeme"
+      MYSQL_ROOT_PASSWORD: "${MYSQL_ROOT_PASSWORD:?zet MYSQL_ROOT_PASSWORD in .env}"
+      MYSQL_DATABASE: "${DATABASE_NAME:-qrcode}"
+      MYSQL_USER: "${DATABASE_USER:-qrcode}"
+      MYSQL_PASSWORD: "${DATABASE_PASSWORD:?zet DATABASE_PASSWORD in .env}"
+    healthcheck:
+      test: ["CMD", "mysqladmin", "ping", "-h", "localhost", "-u", "root", "-p${MYSQL_ROOT_PASSWORD}"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
     networks:
       - php-dynamic-qrcode-network
 
 volumes:
   php_dynamic_qrcode_db_data:
-  php_dynamic_qrcode_config_data:
   php_dynamic_qrcode_saved_qrcode_data:
 
 networks:
   php-dynamic-qrcode-network:
-    driver: bridge
\ No newline at end of file
+    driver: bridge
diff --git a/nginx.conf b/nginx.conf
new file mode 100644
index 0000000..8c33173
--- /dev/null
+++ b/nginx.conf
@@ -0,0 +1,34 @@
+server {
+    listen 80;
+    server_name _;
+    root /var/www/html;
+    index index.php;
+
+    client_max_body_size 20m;
+
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header Referrer-Policy "same-origin" always;
+
+    location / {
+        try_files $uri $uri/ /index.php$is_args$args;
+    }
+
+    location ~ \.php$ {
+        fastcgi_pass php-dynamic-qrcode:9000;
+        fastcgi_index index.php;
+        include fastcgi_params;
+        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
+    }
+
+    # Statisch gegenereerde qrcodes mogen gedownload worden, maar niet als PHP uitgevoerd.
+    location /saved_qrcode/ {
+        location ~ \.php$ {
+            deny all;
+        }
+    }
+
+    location ~ /\. {
+        deny all;
+    }
+}
diff --git a/src/authenticate.php b/src/authenticate.php
index 9a80d63..5e65f78 100644
--- a/src/authenticate.php
+++ b/src/authenticate.php
@@ -1,66 +1,89 @@
 <?php
 
-
-require_once 'config/config.php';
-session_start();
+require_once 'includes/bootstrap.php';
 
 if ($_SERVER['REQUEST_METHOD'] === 'POST')
 {
+	csrf_verify_or_die();
+
 	$username = filter_input(INPUT_POST, 'username');
 	$password = filter_input(INPUT_POST, 'password');
 	$remember = filter_input(INPUT_POST, 'remember');
 
+	if (!$username || !$password) {
+		$_SESSION['login_failure'] = 'Invalid username or password';
+		header('Location: login.php');
+		exit;
+	}
+
+	if (qr_is_login_locked_out($username)) {
+		$_SESSION['login_failure'] = 'Too many failed login attempts. Try again in 15 minutes.';
+		header('Location: login.php');
+		exit;
+	}
+
 	// Get DB instance.
 	$db = getDbInstance();
 
 	$db->where('username', $username);
 	$row = $db->getOne('users');
 
-	if ($db->count >= 1)
+	if ($db->count >= 1 && password_verify($password, $row['password']))
     {
-		$db_password = $row['password'];
+		qr_record_login_attempt($username, true);
+
+		// Voorkom session fixation: nieuwe sessie-id na een geslaagde login.
+		session_regenerate_id(true);
+
+		$_SESSION['user_logged_in'] = TRUE;
+		$_SESSION['type'] = $row['type'];
+        $_SESSION['user_id'] = $row['id'];
+		$_SESSION['username'] = $row['username'];
+		$_SESSION['must_change_password'] = !empty($row['must_change_password']);
+		$_SESSION['last_activity'] = time();
+
+		audit_log('login_success');
+
 		$user_id = $row['id'];
 
-		if (password_verify($password, $db_password))
+		if ($remember)
         {
-			$_SESSION['user_logged_in'] = TRUE;
-			$_SESSION['type'] = $row['type'];
-            $_SESSION['user_id'] = $row['id'];
+			$series_id = randomString(16);
+			$remember_token = getSecureRandomToken(20);
+			$encryted_remember_token = password_hash($remember_token,PASSWORD_DEFAULT);
 
-			if ($remember)
-            {
-				$series_id = randomString(16);
-				$remember_token = getSecureRandomToken(20);
-				$encryted_remember_token = password_hash($remember_token,PASSWORD_DEFAULT);
+			$expiry_time = date('Y-m-d H:i:s', strtotime(' + 30 days'));
+			$expires = strtotime($expiry_time);
+			$is_https = isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off';
 
-				$expiry_time = date('Y-m-d H:i:s', strtotime(' + 30 days'));
-				$expires = strtotime($expiry_time);
+			$cookie_options = [
+				'expires' => $expires,
+				'path' => '/',
+				'secure' => $is_https,
+				'httponly' => true,
+				'samesite' => 'Lax',
+			];
 
-				setcookie('series_id', $series_id, $expires, '/');
-				setcookie('remember_token', $remember_token, $expires, '/');
+			setcookie('series_id', $series_id, $cookie_options);
+			setcookie('remember_token', $remember_token, $cookie_options);
 
-				$db = getDbInstance();
-				$db->where ('id',$user_id);
+			$db = getDbInstance();
+			$db->where ('id',$user_id);
 
-				$update_remember = array(
-					'series_id'=> $series_id,
-					'remember_token' => $encryted_remember_token,
-					'expires' =>$expiry_time
-				);
-				$db->update('users', $update_remember);
-			}
-			// Authentication successfull redirect user
-			header('Location: index.php');
-		}
-        else
-        {
-			$_SESSION['login_failure'] = 'Invalid username or password';
-			header('Location: login.php');
+			$update_remember = array(
+				'series_id'=> $series_id,
+				'remember_token' => $encryted_remember_token,
+				'expires' =>$expiry_time
+			);
+			$db->update('users', $update_remember);
 		}
+		// Authentication successfull redirect user
+		header('Location: index.php');
 		exit;
 	}
     else
     {
+		qr_record_login_attempt($username, false);
 		$_SESSION['login_failure'] = 'Invalid username or password';
 		header('Location: login.php');
 		exit;
diff --git a/src/bulk_action.php b/src/bulk_action.php
index 0f66775..7aa5e3e 100644
--- a/src/bulk_action.php
+++ b/src/bulk_action.php
@@ -1,9 +1,14 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
+require_once BASE_PATH . '/includes/auth_validate.php';
 require_once BASE_PATH . '/lib/DynamicQrcode/DynamicQrcode.php';
 require_once BASE_PATH . '/lib/StaticQrcode/StaticQrcode.php';
 
+header('Content-Type: application/json');
+csrf_verify_header_or_die();
+
+$allowed_types = ['dynamic', 'static'];
+
 if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     $db = getDbInstance();
     $json = json_decode(file_get_contents('php://input'), true);
@@ -12,8 +17,8 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
         $params = $json['params'];
         $files = [];
 
-        if (isset($json['type'])) {
-            $type = filter_var($json['type'], FILTER_SANITIZE_FULL_SPECIAL_CHARS);
+        if (isset($json['type']) && in_array($json['type'], $allowed_types, true)) {
+            $type = $json['type'];
         } else {
             echo json_encode([
                 'data' => 'Type action field in the request.',
@@ -31,9 +36,15 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
         }
 
         foreach ($params as $param) {
-            $row = $db->where('id', $param);
+            $db->where('id', $param);
+            if ($_SESSION['type'] !== 'super') {
+                $db->where('id_owner', $_SESSION['user_id']);
+                $db->orWhere('id_owner', NULL, 'IS');
+            }
             $row = $db->getOne("{$type}_qrcodes");
-            @$files[] = SAVED_QRCODE_FOLDER . $row['qrcode'];
+            if ($row !== NULL) {
+                $files[] = SAVED_QRCODE_FOLDER . $row['qrcode'];
+            }
         }
 
         $zip = new ZipArchive();
@@ -50,6 +61,8 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
 
         $zip->close();
 
+        audit_log('bulk_download', $type, implode(',', $params));
+
         echo json_encode([
             'data' => $url_path,
             'status' => 200
@@ -57,10 +70,9 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
         exit();
     } else if($json["action"] == "delete") {
         $params = $json['params'];
-        $files = [];
 
-        if (isset($json['type'])) {
-            $type = filter_var($json['type'], FILTER_SANITIZE_FULL_SPECIAL_CHARS);
+        if (isset($json['type']) && in_array($json['type'], $allowed_types, true)) {
+            $type = $json['type'];
         } else {
             echo json_encode([
                 'data' => 'Type action field in the request.',
@@ -79,16 +91,15 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
 
         if($type == "dynamic")
             $instance = new DynamicQrcode();
-        else if($type == "static")
-            $instance = new StaticQrcode();
         else
-            die("Type not allowed");
+            $instance = new StaticQrcode();
 
         foreach ($params as $param) {
-            $a = 0;
             $instance->deleteQrcode($param, true);
         }
 
+        audit_log('bulk_delete', $type, implode(',', $params));
+
         echo json_encode([
             'action' => "delete",
             'data' => "Qrcode deleted",
@@ -96,9 +107,12 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
         ]);
         exit();
 
-    } else
-        exit("Action not allowed");
+    } else {
+        echo json_encode(['data' => 'Action not allowed', 'status' => 400]);
+        exit();
+    }
 } else {
-    exit('Direct access to this script not allowed.');
+    http_response_code(405);
+    echo json_encode(['data' => 'Direct access to this script not allowed.', 'status' => 405]);
+    exit();
 }
-?>
\ No newline at end of file
diff --git a/src/change_password.php b/src/change_password.php
new file mode 100644
index 0000000..0117c2d
--- /dev/null
+++ b/src/change_password.php
@@ -0,0 +1,99 @@
+<?php
+require_once 'includes/bootstrap.php';
+
+if (empty($_SESSION['user_logged_in'])) {
+    header('Location: login.php');
+    exit;
+}
+
+$forced = !empty($_SESSION['must_change_password']);
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    csrf_verify_or_die();
+
+    $current_password = $_POST['current_password'] ?? '';
+    $new_password = $_POST['new_password'] ?? '';
+    $confirm_password = $_POST['confirm_password'] ?? '';
+
+    $db = getDbInstance();
+    $db->where('id', $_SESSION['user_id']);
+    $user = $db->getOne('users');
+
+    if ($user === NULL || !password_verify($current_password, $user['password'])) {
+        $_SESSION['failure'] = 'Current password is incorrect.';
+    } elseif (strlen($new_password) < 10) {
+        $_SESSION['failure'] = 'New password must be at least 10 characters long.';
+    } elseif ($new_password !== $confirm_password) {
+        $_SESSION['failure'] = 'New password and confirmation do not match.';
+    } elseif ($new_password === $current_password) {
+        $_SESSION['failure'] = 'New password must be different from the current password.';
+    } else {
+        $db = getDbInstance();
+        $db->where('id', $_SESSION['user_id']);
+        $db->update('users', [
+            'password' => password_hash($new_password, PASSWORD_DEFAULT),
+            'must_change_password' => 0,
+            'password_changed_at' => date('Y-m-d H:i:s'),
+        ]);
+
+        $_SESSION['must_change_password'] = false;
+        audit_log('password_changed');
+
+        $_SESSION['success'] = 'Password updated successfully.';
+        header('Location: index.php');
+        exit;
+    }
+}
+?>
+<!DOCTYPE html>
+<html lang="en">
+<title>Change password - Qrcode Generator</title>
+<?php include './includes/head.php'; ?>
+
+<body class="login-page" style="min-height: 512.391px;">
+    <div class="login-box">
+  <div class="login-logo">
+    <img src="dist/img/DynamicQRCode_Original.png" style="width: 95%; height: 95%">
+  </div>
+
+  <div class="card">
+    <div class="card-body login-card-body">
+      <p class="login-box-msg">
+        <?php echo $forced
+            ? 'You must change your password before continuing.'
+            : 'Change your password'; ?>
+      </p>
+
+      <?php include './includes/flash_messages.php'; ?>
+
+      <form method="POST" action="change_password.php">
+        <?php echo csrf_field(); ?>
+        <div class="input-group mb-3">
+          <input type="password" name="current_password" class="form-control" placeholder="Current password" required="required" autocomplete="current-password">
+        </div>
+        <div class="input-group mb-3">
+          <input type="password" name="new_password" class="form-control" placeholder="New password (min. 10 characters)" required="required" minlength="10" autocomplete="new-password">
+        </div>
+        <div class="input-group mb-3">
+          <input type="password" name="confirm_password" class="form-control" placeholder="Confirm new password" required="required" minlength="10" autocomplete="new-password">
+        </div>
+        <div class="row">
+          <div class="col-12">
+            <button type="submit" class="btn btn-primary btn-block">Update password</button>
+          </div>
+        </div>
+      </form>
+
+      <?php if (!$forced): ?>
+        <p class="mt-3 text-center"><a href="index.php">Back to dashboard</a></p>
+      <?php endif; ?>
+    </div>
+  </div>
+</div>
+
+<script src="../../plugins/jquery/jquery.min.js"></script>
+<script src="../../plugins/bootstrap/js/bootstrap.bundle.min.js"></script>
+<script src="../../dist/js/adminlte.js"></script>
+
+</body>
+</html>
diff --git a/src/dist/js/custom.js b/src/dist/js/custom.js
index 7653209..e0bffbd 100644
--- a/src/dist/js/custom.js
+++ b/src/dist/js/custom.js
@@ -470,6 +470,9 @@
       data: JSON.stringify(data),
       dataType: "json",
       contentType: 'application/json',
+      headers: {
+        'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content')
+      },
       success: (res) => {
         if (res.status == 200) {
           if(data["action"] === "download") {
diff --git a/src/dynamic_qrcode.php b/src/dynamic_qrcode.php
index a466d3c..5e846f6 100644
--- a/src/dynamic_qrcode.php
+++ b/src/dynamic_qrcode.php
@@ -1,11 +1,14 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
 require_once BASE_PATH.'/includes/auth_validate.php';
 require_once BASE_PATH . '/lib/DynamicQrcode/DynamicQrcode.php';
 
 $dynamic_qrcode_instance = new DynamicQrcode();
 
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    csrf_verify_or_die();
+}
+
 $edit = false;
 if($_SERVER["REQUEST_METHOD"] === "GET" && isset($_GET["edit"]) && $_GET["edit"] == "true" && isset($_GET["id"])) {
     $edit = true;
@@ -83,6 +86,7 @@ if($_SERVER["REQUEST_METHOD"] === "POST" && !isset($_POST["edit"])) {
                     <h3 class="card-title">Enter the requested data</h3>
                 </div>
                 <form class="form" action="" method="post" id="dynamic_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
                     <div class="card-body">
                         <?php
                             if($edit)
diff --git a/src/dynamic_qrcodes.php b/src/dynamic_qrcodes.php
index 969ed32..58375a3 100644
--- a/src/dynamic_qrcodes.php
+++ b/src/dynamic_qrcodes.php
@@ -1,6 +1,5 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
 require_once BASE_PATH . '/includes/auth_validate.php';
 require_once BASE_PATH . '/lib/DynamicQrcode/DynamicQrcode.php';
 
diff --git a/src/forms/form_users.php b/src/forms/form_users.php
index 55dde3e..e0d2aa1 100644
--- a/src/forms/form_users.php
+++ b/src/forms/form_users.php
@@ -20,7 +20,7 @@
                     <span class="input-group-text"><i class="fa fa-lock"></i></span>
                 </div>
                 
-                <input type="password" name="password" placeholder="Password" class="form-control" required="required" autocomplete="off">
+                <input type="password" name="password" placeholder="<?php echo ($edit) ? 'Leave blank to keep current password' : 'Password'; ?>" class="form-control" <?php echo ($edit) ? '' : 'required="required"'; ?> minlength="10" autocomplete="off">
             </div>
         </div>
     </div>
diff --git a/src/forms/static/2fa.php b/src/forms/static/2fa.php
index 4417a4f..907b993 100644
--- a/src/forms/static/2fa.php
+++ b/src/forms/static/2fa.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=2fa" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/bitcoin.php b/src/forms/static/bitcoin.php
index 3c6c8fa..0d0cebd 100644
--- a/src/forms/static/bitcoin.php
+++ b/src/forms/static/bitcoin.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=bitcoin" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
  <!-- Input forms -->   
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/bookmark.php b/src/forms/static/bookmark.php
index 1ebca16..97aba8c 100644
--- a/src/forms/static/bookmark.php
+++ b/src/forms/static/bookmark.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=bookmark" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/email.php b/src/forms/static/email.php
index 39c0349..d1ab83e 100644
--- a/src/forms/static/email.php
+++ b/src/forms/static/email.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=email" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/event.php b/src/forms/static/event.php
index e2aa162..1a92159 100644
--- a/src/forms/static/event.php
+++ b/src/forms/static/event.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=event" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-4">
diff --git a/src/forms/static/location.php b/src/forms/static/location.php
index 8c5b833..597afb0 100644
--- a/src/forms/static/location.php
+++ b/src/forms/static/location.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=location" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
     <div class="col-sm-4">
diff --git a/src/forms/static/paypal.php b/src/forms/static/paypal.php
index 5de6f39..f709937 100644
--- a/src/forms/static/paypal.php
+++ b/src/forms/static/paypal.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=paypal" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/phone.php b/src/forms/static/phone.php
index 6214b92..cd7b957 100644
--- a/src/forms/static/phone.php
+++ b/src/forms/static/phone.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=phone" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/skype.php b/src/forms/static/skype.php
index abe3f64..3be9b3c 100644
--- a/src/forms/static/skype.php
+++ b/src/forms/static/skype.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=skype" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
     <div class="col-sm-4">
diff --git a/src/forms/static/sms.php b/src/forms/static/sms.php
index df819f1..b060a46 100644
--- a/src/forms/static/sms.php
+++ b/src/forms/static/sms.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=sms" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/text.php b/src/forms/static/text.php
index 4d9022c..2942e23 100644
--- a/src/forms/static/text.php
+++ b/src/forms/static/text.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=text" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
     <div class="col-sm-6">
diff --git a/src/forms/static/vcard.php b/src/forms/static/vcard.php
index 199e43e..79b89d4 100644
--- a/src/forms/static/vcard.php
+++ b/src/forms/static/vcard.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=vcard" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <!-- First row -->
diff --git a/src/forms/static/whatsapp.php b/src/forms/static/whatsapp.php
index fed34ad..255ce98 100644
--- a/src/forms/static/whatsapp.php
+++ b/src/forms/static/whatsapp.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=whatsapp" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/static/wifi.php b/src/forms/static/wifi.php
index 64ab512..2f6a257 100644
--- a/src/forms/static/wifi.php
+++ b/src/forms/static/wifi.php
@@ -1,4 +1,5 @@
 <form class="form" action="static_qrcode.php?type=wifi" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
     <?php include BASE_PATH.'/forms/qrcode_options.php'; ?>
 <!-- Input forms -->
 <div class="col-sm-12 mb-2">
diff --git a/src/forms/table_dynamic.php b/src/forms/table_dynamic.php
index 24e590f..608600a 100644
--- a/src/forms/table_dynamic.php
+++ b/src/forms/table_dynamic.php
@@ -3,6 +3,7 @@
         <div id="err-msg"></div>
         <div class="bulk-action-wrapper">
             <form id="bulk-action" action="bulk_action.php" method="POST">
+<?php echo csrf_field(); ?>
                 <div class="col-sm-12 mb-2" style="margin-left: 10px">
                     <div class="row">
                         <div class="col-5 col-md-2">
@@ -100,6 +101,7 @@
 <div class="modal fade" id="delete-modal" role="dialog">
     <div class="modal-dialog">
         <form action="dynamic_qrcode.php" method="POST">
+<?php echo csrf_field(); ?>
             <!-- Modal content -->
 
             <div class="modal-content">
diff --git a/src/forms/table_static.php b/src/forms/table_static.php
index 23a72ad..64125d1 100644
--- a/src/forms/table_static.php
+++ b/src/forms/table_static.php
@@ -3,6 +3,7 @@
         <div id="err-msg"></div>
         <div class="bulk-action-wrapper">
             <form id="bulk-action" action="bulk_action.php" method="POST">
+<?php echo csrf_field(); ?>
                 <div class="col-sm-12 mb-2" style="margin-left: 10px">
                     <div class="row">
                         <div class="col-5 col-md-2">
@@ -96,6 +97,7 @@
 <div class="modal fade" id="delete-modal" role="dialog">
     <div class="modal-dialog">
         <form action="static_qrcode.php" method="POST">
+<?php echo csrf_field(); ?>
             <!-- Modal content -->
 
             <div class="modal-content">
diff --git a/src/forms/table_users.php b/src/forms/table_users.php
index d78feea..6b2eeeb 100644
--- a/src/forms/table_users.php
+++ b/src/forms/table_users.php
@@ -47,6 +47,7 @@
 <div class="modal fade" id="delete-modal" role="dialog">
     <div class="modal-dialog">
         <form action="user.php" method="POST">
+<?php echo csrf_field(); ?>
             <!-- Modal content -->
 
             <div class="modal-content">
diff --git a/src/includes/bootstrap.php b/src/includes/bootstrap.php
new file mode 100644
index 0000000..9c3ca53
--- /dev/null
+++ b/src/includes/bootstrap.php
@@ -0,0 +1,14 @@
+<?php
+/**
+ * Centrale bootstrap voor elke entrypoint: config laden, sessie starten met
+ * verharde instellingen, sessie-timeout en verplichte wachtwoordwijziging afdwingen.
+ *
+ * Vervangt de losse "session_start(); require_once 'config/config.php';" aanroepen.
+ */
+
+require_once __DIR__ . '/../config/config.php';
+require_once __DIR__ . '/security.php';
+
+qr_session_start();
+qr_enforce_session_timeout();
+qr_enforce_password_change();
diff --git a/src/includes/head.php b/src/includes/head.php
index f120913..4948d85 100644
--- a/src/includes/head.php
+++ b/src/includes/head.php
@@ -1,6 +1,7 @@
 <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <meta http-equiv="x-ua-compatible" content="ie=edge">
+  <meta name="csrf-token" content="<?php echo csrf_token(); ?>">
 
   <!-- Font Awesome Icons -->
   <link rel="stylesheet" href="plugins/fontawesome-free/css/all.min.css">
diff --git a/src/includes/navbar.php b/src/includes/navbar.php
index 817bf1f..6f48670 100644
--- a/src/includes/navbar.php
+++ b/src/includes/navbar.php
@@ -16,14 +16,10 @@
         </a>
         <div class="dropdown-menu dropdown-menu-lg dropdown-menu-right">
           <div class="dropdown-divider"></div>
-          <!--<a href="#" class="dropdown-item">
-            <i class="fas fa-user"></i> Profile
+          <a href="./change_password.php" class="dropdown-item">
+            <i class="fas fa-key"></i> Change password
           </a>
           <div class="dropdown-divider"></div>
-          <a href="#" class="dropdown-item">
-            <i class="fa fa-cog"></i> Settings
-          </a>-->
-          <div class="dropdown-divider"></div>
           <a href="./logout.php" class="dropdown-item">
             <i class="fas fa-sign-out-alt"></i> Logout
           </a>
diff --git a/src/includes/security.php b/src/includes/security.php
new file mode 100644
index 0000000..a28ba65
--- /dev/null
+++ b/src/includes/security.php
@@ -0,0 +1,161 @@
+<?php
+/**
+ * Fase 1 security hardening: sessiebeheer, CSRF, rate limiting, audit log.
+ * Wordt geladen via includes/bootstrap.php, dat als eerste in elke entrypoint hoort te staan.
+ */
+
+define('SESSION_IDLE_TIMEOUT', 30 * 60); // 30 minuten inactiviteit -> uitloggen
+define('LOGIN_MAX_ATTEMPTS', 5);
+define('LOGIN_LOCKOUT_WINDOW', 15 * 60); // 15 minuten
+
+/**
+ * Start de sessie met verharde cookie-instellingen. Moet vóór elke output aangeroepen worden.
+ */
+function qr_session_start() {
+    if (session_status() === PHP_SESSION_ACTIVE) {
+        return;
+    }
+
+    $is_https = isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off';
+
+    ini_set('session.gc_maxlifetime', (string) SESSION_IDLE_TIMEOUT);
+    ini_set('session.use_strict_mode', '1');
+
+    session_set_cookie_params([
+        'lifetime' => 0,
+        'path' => '/',
+        'domain' => '',
+        'secure' => $is_https,
+        'httponly' => true,
+        'samesite' => 'Lax',
+    ]);
+
+    session_start();
+}
+
+function qr_client_ip() {
+    return $_SERVER['REMOTE_ADDR'] ?? '0.0.0.0';
+}
+
+/**
+ * Logt de gebruiker uit als de sessie te lang inactief is geweest.
+ */
+function qr_enforce_session_timeout() {
+    if (empty($_SESSION['user_logged_in'])) {
+        return;
+    }
+
+    $now = time();
+
+    if (isset($_SESSION['last_activity']) && ($now - $_SESSION['last_activity']) > SESSION_IDLE_TIMEOUT) {
+        $_SESSION = [];
+        $_SESSION['login_failure'] = 'Je sessie is verlopen wegens inactiviteit. Log opnieuw in.';
+        header('Location: login.php');
+        exit;
+    }
+
+    $_SESSION['last_activity'] = $now;
+}
+
+/**
+ * Stuurt ingelogde gebruikers met een verplichte wachtwoordwijziging naar change_password.php,
+ * behalve op de wijzigingspagina en logout zelf.
+ */
+function qr_enforce_password_change() {
+    if (empty($_SESSION['user_logged_in']) || empty($_SESSION['must_change_password'])) {
+        return;
+    }
+
+    $current_script = basename(parse_url($_SERVER['SCRIPT_NAME'], PHP_URL_PATH));
+    $exempt = ['change_password.php', 'logout.php'];
+
+    if (in_array($current_script, $exempt, true)) {
+        return;
+    }
+
+    header('Location: change_password.php');
+    exit;
+}
+
+/**
+ * CSRF-bescherming
+ */
+function csrf_token() {
+    if (empty($_SESSION['csrf_token'])) {
+        $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
+    }
+    return $_SESSION['csrf_token'];
+}
+
+function csrf_field() {
+    return '<input type="hidden" name="csrf_token" value="' . htmlspecialchars(csrf_token(), ENT_QUOTES, 'UTF-8') . '">';
+}
+
+function csrf_is_valid($token) {
+    return isset($_SESSION['csrf_token']) && is_string($token) && hash_equals($_SESSION['csrf_token'], $token);
+}
+
+/**
+ * Voor klassieke form-POSTs: verwacht een verborgen veld "csrf_token".
+ */
+function csrf_verify_or_die() {
+    if (!csrf_is_valid($_POST['csrf_token'] ?? '')) {
+        http_response_code(403);
+        exit('403 Forbidden: invalid or missing CSRF token.');
+    }
+}
+
+/**
+ * Voor JSON/AJAX-endpoints (bv. bulk_action.php): verwacht header X-CSRF-Token.
+ */
+function csrf_verify_header_or_die() {
+    $token = $_SERVER['HTTP_X_CSRF_TOKEN'] ?? '';
+    if (!csrf_is_valid($token)) {
+        http_response_code(403);
+        header('Content-Type: application/json');
+        echo json_encode(['data' => 'Invalid or missing CSRF token', 'status' => 403]);
+        exit;
+    }
+}
+
+/**
+ * Rate limiting op login
+ */
+function qr_record_login_attempt($username, $success) {
+    $db = getDbInstance();
+    $db->insert('login_attempts', [
+        'username' => $username,
+        'ip_address' => qr_client_ip(),
+        'success' => $success ? 1 : 0,
+        'attempted_at' => date('Y-m-d H:i:s'),
+    ]);
+}
+
+function qr_is_login_locked_out($username) {
+    $db = getDbInstance();
+    $window_start = date('Y-m-d H:i:s', time() - LOGIN_LOCKOUT_WINDOW);
+
+    $db->where('username', $username);
+    $db->where('success', 0);
+    $db->where('attempted_at', $window_start, '>=');
+    $count = $db->getValue('login_attempts', 'count(*)');
+
+    return $count !== null && $count >= LOGIN_MAX_ATTEMPTS;
+}
+
+/**
+ * Audit log
+ */
+function audit_log($action, $target_type = null, $target_id = null) {
+    $db = getDbInstance();
+    $db->insert('audit_log', [
+        'user_id' => $_SESSION['user_id'] ?? null,
+        'username' => $_SESSION['username'] ?? null,
+        'action' => $action,
+        'target_type' => $target_type,
+        'target_id' => $target_id !== null ? (string) $target_id : null,
+        'ip_address' => qr_client_ip(),
+        'user_agent' => substr($_SERVER['HTTP_USER_AGENT'] ?? '', 0, 255),
+        'created_at' => date('Y-m-d H:i:s'),
+    ]);
+}
diff --git a/src/index.php b/src/index.php
index 5b6fbc9..88da949 100644
--- a/src/index.php
+++ b/src/index.php
@@ -1,15 +1,5 @@
 <?php
-//Use httponly flag
-ini_set('session.cookie_httponly', 1);
-
-//Use only cookies
-ini_set('session.use_only_cookies', 1);
-
-//Use secure flag
-ini_set('session.cookie_secure', 1);
-
-session_start();
-require_once './config/config.php';
+require_once 'includes/bootstrap.php';
 require_once 'includes/auth_validate.php';
 
 $db = getDbInstance();
diff --git a/src/lib/DynamicQrcode/DynamicQrcode.php b/src/lib/DynamicQrcode/DynamicQrcode.php
index c484b70..f2c61a8 100644
--- a/src/lib/DynamicQrcode/DynamicQrcode.php
+++ b/src/lib/DynamicQrcode/DynamicQrcode.php
@@ -56,6 +56,8 @@ class DynamicQrcode {
      * We save into db the url of qrcode image
      */
     public function addQrcode($input_data) {
+        $this->validateLink($input_data['link'] ?? '');
+
         if($input_data['id_owner'] != "")
             $data_to_db['id_owner'] = $input_data['id_owner'];
         else
@@ -79,6 +81,8 @@ class DynamicQrcode {
      * 
      */
     public function editQrcode($input_data) {
+        $this->validateLink($input_data['link'] ?? '');
+
         if($input_data['id_owner'] != "")
             $data_to_db['id_owner'] = $input_data['id_owner'];
         else
@@ -117,6 +121,17 @@ class DynamicQrcode {
     }
 
 
+    /**
+     * Server-side validatie van de redirect-link (verplicht, max. 500 tekens per kolomdefinitie).
+     */
+    private function validateLink($link) {
+        $link = trim((string) $link);
+
+        if ($link === '' || strlen($link) > 500) {
+            $this->failure('Link is required and must be at most 500 characters.');
+        }
+    }
+
     /**
      * Flash message Failure process
      */
diff --git a/src/lib/Qrcode/Qrcode-intchil.php b/src/lib/Qrcode/Qrcode-intchil.php
index d1cda12..6dd3b69 100644
--- a/src/lib/Qrcode/Qrcode-intchil.php
+++ b/src/lib/Qrcode/Qrcode-intchil.php
@@ -20,6 +20,8 @@ class Qrcode {
     private string $table;
     private string $redirect_url;
 
+    const ALLOWED_FORMATS = ['png', 'gif', 'jpeg', 'jpg', 'svg', 'svgbw', 'eps'];
+
     /**
      *
      */
@@ -43,6 +45,33 @@ class Qrcode {
     {
     }
 
+    /**
+     * Voorkomt path traversal / arbitrary file write via een gemanipuleerde bestandsnaam.
+     */
+    private function sanitizeFilename($filename) {
+        $filename = trim((string) $filename);
+
+        if ($filename === '' || strlen($filename) > 45) {
+            $this->failure('Filename must be between 1 and 45 characters.');
+        }
+
+        if (preg_match('#[\\/\\\\]#', $filename) || strpos($filename, '..') !== false || strpos($filename, "\0") !== false) {
+            $this->failure('Filename cannot contain path separators.');
+        }
+
+        return $filename;
+    }
+
+    private function validateFormat($format) {
+        $format = strtolower((string) $format);
+
+        if (!in_array($format, self::ALLOWED_FORMATS, true)) {
+            $this->failure('Invalid qr code format.');
+        }
+
+        return $format;
+    }
+
     public function getQrcode($id) {
         $db = getDbInstance();
 
@@ -94,6 +123,9 @@ class Qrcode {
     public function addQrcode($input_data, $data_to_db, $data_to_qrcode) {
         $options = $this->setOptions($input_data);
 
+        $data_to_db['filename'] = $this->sanitizeFilename($data_to_db['filename']);
+        $data_to_db['format'] = $this->validateFormat($data_to_db['format']);
+
         $outputInterface = QRGdImagePNG::class;
         $imageFormat = strtolower($data_to_db['format']);
         $fileExt = $imageFormat;
@@ -305,21 +337,23 @@ class Qrcode {
             $this->failure('You cannot create a new qr code with an existing name on the server!');
         
         if ($last_id){
+            audit_log('qrcode_created', $this->table, $last_id);
             $this->success('Qr code added successfully!');
         }
         else {
             $this->failure('Insert failed: ' . $db->getLastError());
         }
     }
-    
+
     /**
      * Edit qr code
-     * 
+     *
      */
     public function editQrcode($input_data, $data_to_db) {
         $db = getDbInstance();
         $old_qrcode = $this->getQrcode($input_data["id"]);
 
+        $data_to_db['filename'] = $this->sanitizeFilename($data_to_db['filename']);
         $data_to_db['qrcode'] = $data_to_db['filename'].'.'.$old_qrcode["format"];
 
         if(!file_exists(SAVED_QRCODE_DIRECTORY.$data_to_db['filename'].'.'.$old_qrcode["format"]) || $data_to_db['filename'] == $input_data["old_filename"]){
@@ -337,6 +371,7 @@ class Qrcode {
             $this->failure('You cannot edit a qr code with an existing name on the server!');
         
         if ($stat){
+            audit_log('qrcode_updated', $this->table, $input_data['id']);
             $this->success('Qr code updated successfully!');
         }
         else {
@@ -344,10 +379,10 @@ class Qrcode {
         }
     }
 
-    
+
     /**
      * Delete qr code
-     * 
+     *
      */
     public function deleteQrcode($id, $async = false) {
         $db = getDbInstance();
@@ -356,7 +391,11 @@ class Qrcode {
 
         $db->where('id', $id);
         $status = $db->delete($this->table);
-        
+
+        if ($status) {
+            audit_log('qrcode_deleted', $this->table, $id);
+        }
+
         try{
             unlink(SAVED_QRCODE_DIRECTORY.$qrcode["filename"].'.'.$qrcode["format"]);
         }
diff --git a/src/lib/Qrcode/Qrcode.php b/src/lib/Qrcode/Qrcode.php
index 8686d09..1bbd71c 100644
--- a/src/lib/Qrcode/Qrcode.php
+++ b/src/lib/Qrcode/Qrcode.php
@@ -5,6 +5,8 @@ class Qrcode {
     private string $table;
     private string $redirect_url;
 
+    const ALLOWED_FORMATS = ['png', 'gif', 'jpeg', 'jpg', 'svg', 'eps'];
+
     /**
      *
      */
@@ -28,6 +30,33 @@ class Qrcode {
     {
     }
 
+    /**
+     * Voorkomt path traversal / arbitrary file write via een gemanipuleerde bestandsnaam.
+     */
+    private function sanitizeFilename($filename) {
+        $filename = trim((string) $filename);
+
+        if ($filename === '' || strlen($filename) > 45) {
+            $this->failure('Filename must be between 1 and 45 characters.');
+        }
+
+        if (preg_match('#[\\/\\\\]#', $filename) || strpos($filename, '..') !== false || strpos($filename, "\0") !== false) {
+            $this->failure('Filename cannot contain path separators.');
+        }
+
+        return $filename;
+    }
+
+    private function validateFormat($format) {
+        $format = strtolower((string) $format);
+
+        if (!in_array($format, self::ALLOWED_FORMATS, true)) {
+            $this->failure('Invalid qr code format.');
+        }
+
+        return $format;
+    }
+
     public function getQrcode($id) {
         $db = getDbInstance();
 
@@ -79,6 +108,9 @@ class Qrcode {
     public function addQrcode($input_data, $data_to_db, $data_to_qrcode) {
         $options = $this->setOptions($input_data);
 
+        $data_to_db['filename'] = $this->sanitizeFilename($data_to_db['filename']);
+        $data_to_db['format'] = $this->validateFormat($data_to_db['format']);
+
         if(!file_exists(SAVED_QRCODE_DIRECTORY.$data_to_db['filename'].'.'.$data_to_db['format'])){
             $url =
                 'https://api.qrserver.com/v1/create-qr-code/?data='.
@@ -111,6 +143,7 @@ class Qrcode {
             $this->failure('You cannot create a new qr code with an existing name on the server!');
         
         if ($last_id){
+            audit_log('qrcode_created', $this->table, $last_id);
             $this->success('Qr code added successfully!');
         }
         else {
@@ -126,6 +159,7 @@ class Qrcode {
         $db = getDbInstance();
         $old_qrcode = $this->getQrcode($input_data["id"]);
 
+        $data_to_db['filename'] = $this->sanitizeFilename($data_to_db['filename']);
         $data_to_db['qrcode'] = $data_to_db['filename'].'.'.$old_qrcode["format"];
 
         if(!file_exists(SAVED_QRCODE_DIRECTORY.$data_to_db['filename'].'.'.$old_qrcode["format"]) || $data_to_db['filename'] == $input_data["old_filename"]){
@@ -143,6 +177,7 @@ class Qrcode {
             $this->failure('You cannot edit a qr code with an existing name on the server!');
         
         if ($stat){
+            audit_log('qrcode_updated', $this->table, $input_data['id']);
             $this->success('Qr code updated successfully!');
         }
         else {
@@ -162,7 +197,11 @@ class Qrcode {
 
         $db->where('id', $id);
         $status = $db->delete($this->table);
-        
+
+        if ($status) {
+            audit_log('qrcode_deleted', $this->table, $id);
+        }
+
         try{
             unlink(SAVED_QRCODE_DIRECTORY.$qrcode["filename"].'.'.$qrcode["format"]);
         }
diff --git a/src/lib/Users/Users.php b/src/lib/Users/Users.php
index 0851906..044c48f 100644
--- a/src/lib/Users/Users.php
+++ b/src/lib/Users/Users.php
@@ -3,6 +3,8 @@ require_once 'config/config.php';
 
 class Users
 {
+    const ALLOWED_TYPES = ['super', 'admin'];
+
     /**
      *
      */
@@ -10,6 +12,25 @@ class Users
     {
     }
 
+    /**
+     * Server-side validatie van username/type. Geeft een foutmelding terug (string) of null als geldig.
+     */
+    private function validateUsernameAndType($username, $type) {
+        if (!is_string($username) || strlen($username) < 3 || strlen($username) > 50) {
+            return 'Username must be between 3 and 50 characters.';
+        }
+
+        if (!preg_match('/^[a-zA-Z0-9._-]+$/', $username)) {
+            return 'Username may only contain letters, numbers, dots, underscores and hyphens.';
+        }
+
+        if (!in_array($type, self::ALLOWED_TYPES, true)) {
+            return 'Invalid user type.';
+        }
+
+        return null;
+    }
+
     /**
      *
      */
@@ -54,6 +75,15 @@ class Users
     public function addUser($input_data) {
         $db = getDbInstance();
 
+        $validation_error = $this->validateUsernameAndType($input_data['username'] ?? '', $input_data['type'] ?? '');
+        if ($validation_error !== null) {
+            $this->failure($validation_error, 'Location: user.php');
+        }
+
+        if (!isset($input_data['password']) || strlen($input_data['password']) < 10) {
+            $this->failure('Password must be at least 10 characters long.', 'Location: user.php');
+        }
+
         $data_to_db["username"] = $input_data["username"];
         $data_to_db['password'] = password_hash($input_data['password'], PASSWORD_DEFAULT);
         $data_to_db["type"] = $input_data["type"];
@@ -66,8 +96,10 @@ class Users
 
 	    $last_id = $db->insert('users', $data_to_db);
 
-	    if ($last_id)
+	    if ($last_id) {
+		    audit_log('user_created', 'user', $last_id);
 		    $this->success('User added successfully');
+	    }
     }
     
     /**
@@ -77,28 +109,43 @@ class Users
     public function editUser($input_data) {
         $db = getDbInstance();
 
+        $query_string = http_build_query(array(
+            'id' => $input_data["id"],
+            'edit' => "true",
+        ));
+
+        $validation_error = $this->validateUsernameAndType($input_data['username'] ?? '', $input_data['type'] ?? '');
+        if ($validation_error !== null) {
+            $this->failure($validation_error, 'Location: user.php?'.$query_string);
+        }
+
+        if (isset($input_data['password']) && strlen($input_data['password']) > 0 && strlen($input_data['password']) < 10) {
+            $this->failure('Password must be at least 10 characters long.', 'Location: user.php?'.$query_string);
+        }
+
         $db->where('username', $input_data['username']);
         $db->where('id', $input_data["id"], '!=');
         $row = $db->getOne('users');
 
         if (!empty($row['username']))  {
-            $query_string = http_build_query(array(
-                'id' => $input_data["id"],
-                'edit' => "true",
-            ));
             $this->failure('Username already exists', 'Location: user.php?'.$query_string);
         }
 
         $data_to_db["username"] = $input_data["username"];
-        $data_to_db['password'] = password_hash($input_data['password'], PASSWORD_DEFAULT);
         $data_to_db["type"] = $input_data["type"];
 
+        // Alleen wachtwoord overschrijven als er een nieuwe waarde is opgegeven.
+        if (!empty($input_data['password'])) {
+            $data_to_db['password'] = password_hash($input_data['password'], PASSWORD_DEFAULT);
+        }
+
 	    $db->where('id', $input_data["id"]);
 	    $stat = $db->update('users', $data_to_db);
-        
-        if ($stat)
+
+        if ($stat) {
+            audit_log('user_updated', 'user', $input_data['id']);
             $this->success('User updated successfully!');
-        else
+        } else
             $this->failure('Failed to update User: ' . $db->getLastError());
     }
     
@@ -116,9 +163,10 @@ class Users
         $db->where('id', $id);
         $stat = $db->delete('users');
 
-        if ($stat)
+        if ($stat) {
+            audit_log('user_deleted', 'user', $id);
             $this->info('User deleted successfully!');
-        else
+        } else
             $this->failure('Unable to delete user');
     }
     
diff --git a/src/login.php b/src/login.php
index 7c6c46d..6631364 100644
--- a/src/login.php
+++ b/src/login.php
@@ -1,12 +1,12 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
 $token = bin2hex(openssl_random_pseudo_bytes(16));
 
 // If User has already logged in, redirect to dashboard page.
 if (isset($_SESSION['user_logged_in']) && $_SESSION['user_logged_in'] === TRUE)
 {
 	header('Location: index.php');
+	exit;
 }
 
 // If user has previously selected "remember me option": 
@@ -33,9 +33,17 @@ if (isset($_COOKIE['series_id']) && isset($_COOKIE['remember_token']))
                 exit;
             }
 
+			session_regenerate_id(true);
+
 			$_SESSION['user_logged_in'] = TRUE;
             $_SESSION['user_id'] = $row['id'];
 			$_SESSION['type'] = $row['type'];
+			$_SESSION['username'] = $row['username'];
+			$_SESSION['must_change_password'] = !empty($row['must_change_password']);
+			$_SESSION['last_activity'] = time();
+
+			audit_log('login_success_remember');
+
 			header('Location: index.php');
 			exit;
 		}
@@ -71,6 +79,7 @@ if (isset($_COOKIE['series_id']) && isset($_COOKIE['remember_token']))
       <p class="login-box-msg">Sign in to start your session</p>
 
       <form method="POST" action="authenticate.php">
+        <?php echo csrf_field(); ?>
         <div class="input-group mb-3">
           <input type="text" name="username" class="form-control" placeholder="Username" required="required">
           <div class="input-group-append">
diff --git a/src/logout.php b/src/logout.php
index a1dccf2..44b2021 100644
--- a/src/logout.php
+++ b/src/logout.php
@@ -1,10 +1,20 @@
 <?php
-require_once './config/config.php';
-session_start();
+require_once 'includes/bootstrap.php';
+
+if (!empty($_SESSION['user_logged_in'])) {
+    audit_log('logout');
+}
+
+$_SESSION = [];
+
+if (ini_get('session.use_cookies')) {
+    $params = session_get_cookie_params();
+    setcookie(session_name(), '', time() - 42000, $params['path'], $params['domain'], $params['secure'], $params['httponly']);
+}
+
 session_destroy();
 
-
-if(isset($_COOKIE['series_id']) && isset($_COOKIE['remember_token'])){
+if (isset($_COOKIE['series_id']) && isset($_COOKIE['remember_token'])) {
 	clearAuthCookie();
 }
 header('Location:index.php');
diff --git a/src/static_qrcode.php b/src/static_qrcode.php
index e1af943..2d3d160 100644
--- a/src/static_qrcode.php
+++ b/src/static_qrcode.php
@@ -1,11 +1,14 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
 require_once BASE_PATH.'/includes/auth_validate.php';
 require_once BASE_PATH . '/lib/StaticQrcode/StaticQrcode.php';
 
 $static_qrcode_instance = new StaticQrcode();
 
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    csrf_verify_or_die();
+}
+
 $edit = false;
 if($_SERVER["REQUEST_METHOD"] === "GET" && isset($_GET["edit"]) && $_GET["edit"] == "true" && isset($_GET["id"])) {
     $edit = true;
@@ -115,6 +118,7 @@ if($_SERVER["REQUEST_METHOD"] === "POST" && !isset($_POST["edit"])) {
                 </div>
                 <?php if($edit) {?>
                     <form class="form" action="" method="post" id="static_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
                         <div class="card-body">
                             <?php include BASE_PATH . '/forms/form_static_edit.php';?>
                         </div>
diff --git a/src/static_qrcodes.php b/src/static_qrcodes.php
index 2c82254..0165c41 100644
--- a/src/static_qrcodes.php
+++ b/src/static_qrcodes.php
@@ -1,6 +1,5 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
 require_once BASE_PATH . '/includes/auth_validate.php';
 require_once BASE_PATH . '/lib/StaticQrcode/StaticQrcode.php';
 
diff --git a/src/user.php b/src/user.php
index 9356824..bd093cb 100644
--- a/src/user.php
+++ b/src/user.php
@@ -1,6 +1,5 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
 require_once BASE_PATH . '/includes/auth_validate.php';
 require_once BASE_PATH . '/lib/Users/Users.php';
 
@@ -9,6 +8,9 @@ $user_instance = new Users();
 if ($_SESSION['type'] !== 'super')
     $user_instance->failure('Only a "super admin" account can access the admin listing page', 'Location: index.php');
 
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    csrf_verify_or_die();
+}
 
 $edit = false;
 if($_SERVER["REQUEST_METHOD"] === "GET" && isset($_GET["edit"]) && $_GET["edit"] == "true" && isset($_GET["id"])) {
@@ -83,6 +85,7 @@ if($_SERVER["REQUEST_METHOD"] === "POST" && !isset($_POST["edit"])) {
                     <h3 class="card-title">Enter the requested data</h3>
                 </div>
 	            <form class="well form-horizontal" action="" method="post" id="contact_form" enctype="multipart/form-data">
+<?php echo csrf_field(); ?>
 	                <div class="card-body">
 		                <?php include BASE_PATH . '/forms/form_users.php'; ?>
 		            </div>
diff --git a/src/users.php b/src/users.php
index 9f54329..12181de 100644
--- a/src/users.php
+++ b/src/users.php
@@ -1,6 +1,5 @@
 <?php
-session_start();
-require_once 'config/config.php';
+require_once 'includes/bootstrap.php';
 require_once BASE_PATH . '/includes/auth_validate.php';
 require_once BASE_PATH . '/lib/Users/Users.php';