Integrate ModSecurity 3 with SOAR platforms for automated incident response and threat detection

Update system packages and install dependencies

Start by updating your system and installing required packages for ModSecurity 3 compilation and web server integration.

sudo apt update && sudo apt upgrade -y
sudo apt install -y build-essential libcurl4-openssl-dev liblua5.3-dev libfuzzy-dev ssdeep gettext pkg-config libpcre3-dev libxml2-dev libcurl4-openssl-dev libyajl-dev doxygen nginx apache2-dev git autoconf automake libtool libgeoip-dev

sudo dnf update -y
sudo dnf groupinstall -y "Development Tools"
sudo dnf install -y libcurl-devel lua-devel libfuzzy-devel ssdeep gettext-devel pkgconfig pcre-devel libxml2-devel yajl-devel doxygen nginx httpd-devel git autoconf automake libtool GeoIP-devel

Download and compile ModSecurity 3

Clone the ModSecurity 3 source code and compile it with all necessary modules for web application firewall functionality.

cd /opt
sudo git clone --depth 1 -b v3/master --single-branch https://github.com/SpiderLabs/ModSecurity.git
sudo chown -R $USER:$USER /opt/ModSecurity
cd ModSecurity
git submodule init
git submodule update
./build.sh
./configure
make
sudo make install

Install ModSecurity-nginx connector

Download and compile the ModSecurity-nginx connector to integrate ModSecurity 3 with Nginx web server.

cd /opt
sudo git clone --depth 1 https://github.com/SpiderLabs/ModSecurity-nginx.git
sudo chown -R $USER:$USER /opt/ModSecurity-nginx

# Get nginx version for dynamic module compilation
nginx -v 2>&1 | grep -o '[0-9]\+\.[0-9]\+\.[0-9]\+'

# Download nginx source matching your version (replace 1.24.0 with your version)
wget http://nginx.org/download/nginx-1.24.0.tar.gz
tar zxvf nginx-1.24.0.tar.gz
cd nginx-1.24.0

# Configure and build the dynamic module
./configure --with-compat --add-dynamic-module=../ModSecurity-nginx
make modules
sudo cp objs/ngx_http_modsecurity_module.so /etc/nginx/modules/

Download OWASP Core Rule Set

Install the OWASP Core Rule Set (CRS) which provides comprehensive protection rules for common web application attacks.

cd /opt
sudo wget https://github.com/coreruleset/coreruleset/archive/v4.0.0.tar.gz
sudo tar -xzf v4.0.0.tar.gz
sudo mv coreruleset-4.0.0 /opt/coreruleset
sudo cp /opt/coreruleset/crs-setup.conf.example /opt/coreruleset/crs-setup.conf

Create ModSecurity main configuration

Configure ModSecurity 3 with JSON logging format for SOAR platform consumption and structured event data.

SecRuleEngine On
SecRequestBodyAccess On
SecRequestBodyLimit 13107200
SecRequestBodyNoFilesLimit 131072
SecRequestBodyInMemoryLimit 131072
SecRequestBodyLimitAction Reject
SecRule REQUEST_HEADERS:Content-Type "text/xml" "id:'200000',phase:1,t:none,t:lowercase,pass,nolog,ctl:requestBodyProcessor=XML"
SecRule REQUEST_HEADERS:Content-Type "application/xml" "id:'200001',phase:1,t:none,t:lowercase,pass,nolog,ctl:requestBodyProcessor=XML"
SecRule REQUEST_HEADERS:Content-Type "text/xml" "id:'200002',phase:1,t:none,t:lowercase,pass,nolog,ctl:requestBodyProcessor=XML"
SecResponseBodyAccess On
SecResponseBodyMimeType text/plain text/html text/xml
SecResponseBodyLimit 524288
SecResponseBodyLimitAction ProcessPartial
SecTmpDir /tmp/
SecDataDir /tmp/

# JSON Logging Configuration for SOAR Integration
SecAuditEngine On
SecAuditLogRelevantStatus "^(?:5|4(?!04))"
SecAuditLogParts ABIJDEFHZ
SecAuditLogType Serial
SecAuditLog /var/log/modsecurity/audit.log
SecAuditLogFormat JSON

# Enhanced JSON logging with additional fields for SOAR
SecAuditLogStorageDir /var/log/modsecurity/
SecRule RESPONSE_STATUS "@streq 200" "id:999001,phase:5,pass,nolog,setvar:'tx.allowed_request=1'"
SecRule TX:ALLOWED_REQUEST "@eq 1" "id:999002,phase:5,pass,log,msg:'Legitimate request logged for baseline',logdata:'client_ip=%{REMOTE_ADDR} user_agent=%{REQUEST_HEADERS.User-Agent} method=%{REQUEST_METHOD} uri=%{REQUEST_URI}'"

# Custom action for webhook notifications
SecAction "id:999003,phase:1,pass,nolog,setvar:'tx.webhook_url=http://your-soar-platform.example.com/api/webhook/modsecurity'"

SecDebugLog /var/log/modsecurity/debug.log
SecDebugLogLevel 3
SecArgumentSeparator &
SecCookieFormat 0
SecTmpSaveUploadedFiles on
SecUploadDir /opt/modsecurity/var/upload

Create structured JSON logging script

Create a Python script to parse ModSecurity logs and format them for SOAR platform consumption with enriched metadata.

#!/usr/bin/env python3
import json
import re
import requests
import time
from datetime import datetime
import hashlib
import os
import sys

class ModSecuritySOARIntegration:
    def __init__(self, webhook_url, api_key=None):
        self.webhook_url = webhook_url
        self.api_key = api_key
        self.headers = {
            'Content-Type': 'application/json',
            'User-Agent': 'ModSecurity-SOAR-Integration/1.0'
        }
        if api_key:
            self.headers['Authorization'] = f'Bearer {api_key}'
    
    def parse_audit_log(self, log_line):
        """Parse ModSecurity audit log line and extract security event data"""
        try:
            log_data = json.loads(log_line)
            
            # Extract key security indicators
            event = {
                'timestamp': datetime.utcnow().isoformat() + 'Z',
                'source_ip': log_data.get('request', {}).get('remote_addr', ''),
                'request_method': log_data.get('request', {}).get('method', ''),
                'request_uri': log_data.get('request', {}).get('uri', ''),
                'user_agent': log_data.get('request', {}).get('headers', {}).get('User-Agent', ''),
                'host': log_data.get('request', {}).get('headers', {}).get('Host', ''),
                'response_status': log_data.get('response', {}).get('http_code', 0),
                'rules_matched': [],
                'threat_score': 0,
                'severity': 'info'
            }
            
            # Process matched rules
            messages = log_data.get('audit_data', {}).get('messages', [])
            for msg in messages:
                rule_info = {
                    'rule_id': msg.get('details', {}).get('ruleId', ''),
                    'message': msg.get('details', {}).get('msg', ''),
                    'data': msg.get('details', {}).get('data', ''),
                    'file': msg.get('details', {}).get('file', ''),
                    'line': msg.get('details', {}).get('lineNumber', ''),
                    'severity': msg.get('details', {}).get('severity', '')
                }
                event['rules_matched'].append(rule_info)
                
                # Calculate threat score based on rule severity
                severity_scores = {'EMERGENCY': 5, 'ALERT': 4, 'CRITICAL': 4, 'ERROR': 3, 'WARNING': 2, 'NOTICE': 1}
                event['threat_score'] += severity_scores.get(rule_info['severity'].upper(), 1)
            
            # Set overall severity based on threat score
            if event['threat_score'] >= 10:
                event['severity'] = 'critical'
            elif event['threat_score'] >= 5:
                event['severity'] = 'high'
            elif event['threat_score'] >= 3:
                event['severity'] = 'medium'
            else:
                event['severity'] = 'low'
            
            # Generate unique event ID
            event_string = f"{event['timestamp']}{event['source_ip']}{event['request_uri']}"
            event['event_id'] = hashlib.sha256(event_string.encode()).hexdigest()[:16]
            
            return event
            
        except (json.JSONDecodeError, KeyError) as e:
            print(f"Error parsing log line: {e}")
            return None
    
    def send_to_soar(self, event_data):
        """Send security event to SOAR platform via webhook"""
        try:
            # Prepare SOAR-compatible payload
            soar_payload = {
                'alert_type': 'modsecurity_waf',
                'severity': event_data['severity'],
                'timestamp': event_data['timestamp'],
                'source': 'ModSecurity WAF',
                'event_id': event_data['event_id'],
                'indicators': {
                    'ip_address': event_data['source_ip'],
                    'user_agent': event_data['user_agent'],
                    'host': event_data['host'],
                    'request_uri': event_data['request_uri']
                },
                'details': {
                    'method': event_data['request_method'],
                    'response_code': event_data['response_status'],
                    'threat_score': event_data['threat_score'],
                    'matched_rules': event_data['rules_matched']
                },
                'raw_data': event_data
            }
            
            response = requests.post(
                self.webhook_url,
                headers=self.headers,
                json=soar_payload,
                timeout=10
            )
            
            if response.status_code == 200:
                print(f"Successfully sent event {event_data['event_id']} to SOAR platform")
                return True
            else:
                print(f"Failed to send event to SOAR: HTTP {response.status_code}")
                return False
                
        except requests.RequestException as e:
            print(f"Error sending to SOAR platform: {e}")
            return False

def monitor_audit_log(log_file_path, soar_integration):
    """Monitor ModSecurity audit log and send events to SOAR"""
    try:
        with open(log_file_path, 'r') as f:
            # Seek to end of file
            f.seek(0, 2)
            
            while True:
                line = f.readline()
                if line:
                    event = soar_integration.parse_audit_log(line.strip())
                    if event and event['threat_score'] > 0:
                        soar_integration.send_to_soar(event)
                else:
                    time.sleep(1)
                    
    except FileNotFoundError:
        print(f"Audit log file not found: {log_file_path}")
    except KeyboardInterrupt:
        print("Monitoring stopped")

if __name__ == "__main__":
    # Configuration - modify these values for your SOAR platform
    WEBHOOK_URL = os.getenv('MODSEC_SOAR_WEBHOOK', 'http://your-soar-platform.example.com/api/webhook/modsecurity')
    API_KEY = os.getenv('MODSEC_SOAR_API_KEY', '')
    LOG_FILE = '/var/log/modsecurity/audit.log'
    
    soar = ModSecuritySOARIntegration(WEBHOOK_URL, API_KEY)
    monitor_audit_log(LOG_FILE, soar)

Configure Nginx with ModSecurity module

Enable ModSecurity module in Nginx and configure it to use our security rules and logging settings.

# Add at the top of nginx.conf
load_module modules/ngx_http_modsecurity_module.so;

http {
    # ModSecurity configuration
    modsecurity on;
    modsecurity_rules_file /opt/ModSecurity/modsecurity.conf;
    
    # Enable detailed logging
    log_format modsec_json escape=json '{'
        '"time":"$time_iso8601",'
        '"remote_addr":"$remote_addr",'
        '"request":"$request",'
        '"status":$status,'
        '"body_bytes_sent":$body_bytes_sent,'
        '"http_referer":"$http_referer",'
        '"http_user_agent":"$http_user_agent",'
        '"request_time":$request_time,'
        '"upstream_response_time":"$upstream_response_time"'
    '}';
    
    access_log /var/log/nginx/access.log modsec_json;
    error_log /var/log/nginx/error.log warn;
    
    # Include other configurations
    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}

Create virtual host with ModSecurity protection

Configure a virtual host that demonstrates ModSecurity protection with OWASP Core Rule Set integration.

server {
    listen 80;
    server_name example.com www.example.com;
    
    # Enable ModSecurity for this virtual host
    modsecurity on;
    modsecurity_rules_file /opt/ModSecurity/modsecurity.conf;
    
    # Include OWASP Core Rule Set
    modsecurity_rules '
        Include /opt/coreruleset/crs-setup.conf
        Include /opt/coreruleset/rules/*.conf
        
        # Custom rule for SOAR integration
        SecRule REQUEST_URI "@detectSQLi" \
            "id:2001,phase:2,block,msg:SQL Injection Attack,logdata:Matched Data: %{MATCHED_VAR} found within %{MATCHED_VAR_NAME},tag:attack-sqli,severity:CRITICAL"
        
        SecRule ARGS "@detectXSS" \
            "id:2002,phase:2,block,msg:XSS Attack,logdata:Matched Data: %{MATCHED_VAR} found within %{MATCHED_VAR_NAME},tag:attack-xss,severity:CRITICAL"
        
        # Custom action to trigger webhook on high severity events
        SecRule TX:ANOMALY_SCORE "@gt 4" \
            "id:2003,phase:5,pass,exec:/opt/modsecurity/webhook_notify.sh %{TX.ANOMALY_SCORE} %{REMOTE_ADDR} %{REQUEST_URI}"
    ';
    
    location / {
        root /var/www/html;
        index index.html index.htm;
        
        # Additional security headers
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header X-XSS-Protection "1; mode=block" always;
        add_header X-Content-Type-Options "nosniff" always;
    }
    
    # Specific protection for admin areas
    location /admin {
        modsecurity_rules '
            SecRuleRemoveById 920350
            SecRule REQUEST_URI "@beginsWith /admin" \
                "id:3001,phase:1,pass,log,msg:Admin area access,logdata:IP: %{REMOTE_ADDR} URI: %{REQUEST_URI}"
        ';
        
        root /var/www/html;
        index index.html;
    }
}

Create webhook notification script

Create a shell script that triggers immediate webhook notifications for high-severity security events.

#!/bin/bash

# ModSecurity Webhook Notification Script
# Arguments: $1=anomaly_score $2=remote_addr $3=request_uri

ANOMALY_SCORE=$1
REMOTE_ADDR=$2
REQUEST_URI=$3
TIMESTAMP=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
WEBHOOK_URL="${MODSEC_SOAR_WEBHOOK:-http://your-soar-platform.example.com/api/webhook/modsecurity}"
API_KEY="${MODSEC_SOAR_API_KEY:-}"

# Create JSON payload for immediate notification
PAYLOAD=$(cat <

Set up log directories and permissions

Create necessary directories and set appropriate permissions for ModSecurity logging and scripts.

sudo mkdir -p /var/log/modsecurity
sudo mkdir -p /opt/modsecurity/var/upload
sudo chown -R www-data:www-data /var/log/modsecurity
sudo chown -R www-data:www-data /opt/modsecurity/var/upload
sudo chmod 755 /opt/modsecurity/webhook_notify.sh
sudo chmod 755 /opt/modsecurity/soar_integration.py

# Create logrotate configuration
sudo tee /etc/logrotate.d/modsecurity > /dev/null <