Network vulnerability scanner with NMAP and automated CVE reporting

Network Vulnerability Scanner (used NMAP as engine) with Automated CVE Report

Workflow Overview

This n8n workflow provides comprehensive network vulnerability scanning with automated CVE enrichment and professional report generation. It performs Nmap scans, queries the National Vulnerability Database (NVD) for CVE information, generates detailed HTML/PDF reports, and distributes them via Telegram and email.

Key Features

• Automated Network Scanning: Full Nmap service and version detection scan
• CVE Enrichment: Automatic vulnerability lookup using NVD API
• CVSS Scoring: Vulnerability severity assessment with CVSS v3.1/v3.0 scores
• Professional Reporting: HTML reports with detailed findings and recommendations
• PDF Generation: Password-protected PDF reports using Prince XML
• Multi-Channel Distribution: Telegram and email delivery
• Multiple Triggers: Webhook API, web form, manual execution, scheduled scans
• Rate Limiting: Respects NVD API rate limits
• Comprehensive Data: Service detection, CPE matching, CVE details with references

Use Cases

• Regular security audits of network infrastructure
• Compliance scanning for vulnerability management
• Penetration testing reconnaissance phase
• Asset inventory with vulnerability context
• Continuous security monitoring
• Vulnerability assessment reporting for management
• DevSecOps integration for infrastructure testing

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Setup Instructions

Prerequisites

Before setting up this workflow, ensure you have:

System Requirements

• n8n instance (self-hosted) with command execution capability
• Alpine Linux base image (or compatible Linux distribution)
• Minimum 2 GB RAM (4 GB recommended for large scans)
• 2 GB free disk space for dependencies
• Network access to scan targets
• Internet connectivity for NVD API

Required Knowledge

• Basic networking concepts (IP addresses, ports, protocols)
• Understanding of CVE/CVSS vulnerability scoring
• Nmap scanning basics

External Services

• Telegram Bot (optional, for Telegram notifications)
• Email server / SMTP credentials (optional, for email reports)
• NVD API access (public, no API key required but rate-limited)

Step 1: Understanding the Workflow Components

Core Dependencies

Nmap: Network scanner

• Purpose: Port scanning, service detection, version identification
• Usage: Performs TCP SYN scan with service/version detection

nmap-helper: JSON conversion tool

• Repository: https://github.com/net-shaper/nmap-helper
• Purpose: Converts Nmap XML output to JSON format

Prince XML: HTML to PDF converter

• Website: https://www.princexml.com
• Version: 16.1 (Alpine 3.20)
• Purpose: Generates professional PDF reports from HTML
• Features: Password protection, print-optimized formatting

NVD API: Vulnerability database

• Endpoint: https://services.nvd.nist.gov/rest/json/cves/2.0
• Purpose: CVE information, CVSS scores, vulnerability descriptions
• Rate Limit: Public API allows limited requests per minute
• Documentation: https://nvd.nist.gov/developers

Step 2: Telegram Bot Configuration (Optional)

If you want to receive reports via Telegram:

Create Telegram Bot

1. Open Telegram and search for @BotFather
2. Start a chat and send /newbot
3. Follow prompts:
   • Bot name: Network Scanner Bot (or your choice)
   • Username: network_scanner_bot (must end with 'bot')
4. BotFather will provide:
   • Bot token: 123456789:ABCdefGHIjklMNOpqrsTUVwxyz (save this)
   • Bot URL: https://t.me/your_bot_username

Get Your Chat ID

1. Start a chat with your new bot
2. Send any message to the bot
3. Visit: https://api.telegram.org/bot<YOUR_BOT_TOKEN>/getUpdates
4. Find your chat ID in the response
5. Save this chat ID (e.g., 123456789)

Alternative: Group Chat ID

For sending to a group:

1. Add bot to your group
2. Send a message in the group
3. Check getUpdates URL
4. Group chat IDs are negative: -1001234567890

Add Credentials to n8n

1. Navigate to Credentials in n8n
2. Click Add Credential
3. Select Telegram API
4. Fill in:
   • Access Token: Your bot token from BotFather
5. Click Save
6. Test connection if available

Step 3: Email Configuration (Optional)

If you want to receive reports via email:

Add SMTP Credentials to n8n

1. Navigate to Credentials in n8n
2. Click Add Credential
3. Select SMTP
4. Fill in:
   • Host: SMTP server address (e.g., smtp.gmail.com)
   • Port: SMTP port (587 for TLS, 465 for SSL, 25 for unencrypted)
   • User: Your email username
   • Password: Your email password or app password
   • Secure: Enable for TLS/SSL
5. Click Save

Gmail Users:

1. Enable 2-factor authentication
2. Generate app-specific password: https://myaccount.google.com/apppasswords
3. Use app password in n8n credential

Step 4: Import and Configure Workflow

Configure Basic Parameters

Locate "1. Set Parameters" Node:

1. Click the node to open settings
2. Default configuration:
   • network: Input from webhook/form/manual trigger
   • timestamp: Auto-generated (format: yyyyMMdd_HHmmss)
   • report_password: Almafa123456 (change this!)

Change Report Password:

1. Edit report_password assignment
2. Set strong password: 12+ characters, mixed case, numbers, symbols
3. This password will protect the PDF report
4. Save changes

Step 5: Configure Notification Endpoints

Telegram Configuration

Locate "14/a. Send Report in Telegram" Node:

1. Open node settings
2. Update fields:
   • Chat ID: Replace -123456789012 with your actual chat ID
   • Credentials: Select your Telegram credential
3. Save changes

Message customization:

• Current: Sends PDF as document attachment
• Automatic filename: vulnerability_report_<timestamp>.pdf
• No caption by default (add if needed)

Email Configuration

Locate "14/b. Send Report in Email with SMTP" Node:

1. Open node settings
2. Update fields:
   • From Email: [email protected] → Your sender email
   • To Email: [email protected] → Your recipient email
   • Subject: Customize if needed (default includes network target)
   • Text: Email body message
   • Credentials: Select your SMTP credential
3. Save changes

Multiple Recipients: Change toEmail field to comma-separated list:

[email protected], [email protected], [email protected]

Add CC/BCC: In node options, add:

• cc: Carbon copy recipients
• bcc: Blind carbon copy recipients

Step 6: Configure Triggers

The workflow supports 4 trigger methods:

Trigger 1: Webhook API (Production)

Locate "Webhook" Node:

• Path: /vuln-scan
• Method: POST
• Response: Immediate acknowledgment "Process started!"
• Async: Scan runs in background

Trigger 2: Web Form (User-Friendly)

Locate "On form submission" Node:

• Path: /webhook-test/form/target
• Method: GET (form display), POST (form submit)
• Form Title: "Add scan parameters"
• Field: network (required)

Form URL:

https://your-n8n-domain.com/webhook-test/form/target

Users can:

1. Open form URL in browser
2. Enter target network/IP
3. Click submit
4. Receive confirmation

Trigger 3: Manual Execution (Testing)

Locate "Manual Trigger" Node:

• Click to activate
• Opens workflow with "Pre-Set-Target" node
• Default target: scanme.nmap.org (Nmap's official test server)

To change default target:

1. Open "Pre-Set-Target" node
2. Edit network value
3. Enter your test target
4. Save changes

Trigger 4: Scheduled Scans (Automated)

Locate "Schedule Trigger" Node:

• Default: Daily at 1:00 AM
• Uses "Pre-Set-Target" for network

To change schedule:

1. Open node settings
2. Modify trigger time:
   • Hour: 1 (1 AM)
   • Minute: 0
   • Day of week: All days (or select specific days)
3. Save changes

Schedule Examples:

• Every day at 3 AM: Hour: 3, Minute: 0
• Weekly on Monday at 2 AM: Hour: 2, Day: Monday
• Twice daily (8 AM, 8 PM): Create two Schedule Trigger nodes

Step 7: Test the Workflow

Recommended Test Target

Use Nmap's official test server for initial testing:

• Target: scanme.nmap.org
• Purpose: Official Nmap testing server
• Safe: Designed for scanning practice
• Permissions: Public permission to scan

Important: Never scan targets without permission. Unauthorized scanning is illegal.

Manual Test Execution

1. Open workflow in n8n editor
2. Click Manual Trigger node to select it
3. Click Execute Workflow button
4. Workflow will start with scanme.nmap.org as target

Monitor Execution

Watch nodes turn green as they complete:

1. Need to Add Helper?: Checks if nmap-helper installed
2. Add NMAP-HELPER: Installs helper (if needed, ~2-3 minutes)
3. Optional Params Setter: Sets scan parameters
4. 2. Execute Nmap Scan: Runs scan (5-30 minutes depending on target)
5. 3. Parse NMAP JSON to Services: Extracts services (~1 second)
6. 5. CVE Enrichment Loop: Queries NVD API (1 second per service)
7. 8-10. Report Generation: Creates HTML/PDF reports (~5-10 seconds)
8. 12. Convert to PDF: Generates password-protected PDF (~10 seconds)
9. 14a/14b. Distribution: Sends reports

Check Outputs

Click nodes to view outputs:

• 3. Parse NMAP JSON: View discovered services
• 5. CVE Enrichment: See vulnerabilities found
• 8. Prepare Report Structure: Check statistics
• 13. Read Report PDF: Download report to verify

Verify Distribution

Telegram:

• Open Telegram chat with your bot
• Check for PDF document
• Download and open with password

Email:

• Check inbox for report email
• Verify subject line includes target network
• Download PDF attachment
• Open with password

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How to Use

Understanding the Scan Process

Initiating Scans

Method 1: Webhook API

Use curl or any HTTP client and add "network" parameter in a POST request.

Response:

Process started!

Scan runs asynchronously. You'll receive results via configured channels (Telegram/Email).

Method 2: Web Form

1. Open form URL in browser:

   https://your-n8n.com/webhook-test/form/target
   

2. Fill in form:

   • network: Enter target (IP, range, domain)

3. Click Submit

4. Receive confirmation

5. Wait for report delivery

Advantages:

• No command line needed
• User-friendly interface
• Input validation
• Good for non-technical users

Method 3: Manual Execution

For testing or one-off scans:

1. Open workflow in n8n
2. Edit "Pre-Set-Target" node:
   • Change network value to your target
3. Click Manual Trigger node
4. Click Execute Workflow
5. Monitor progress in real-time

Advantages:

• See execution in real-time
• Debug issues immediately
• Test configuration changes
• View intermediate outputs

Method 4: Scheduled Scans

For regular, automated security audits:

1. Configure "Schedule Trigger" node with desired time
2. Configure "Pre-Set-Target" node with default target
3. Activate workflow
4. Scans run automatically on schedule

Advantages:

• Automated security monitoring
• Regular compliance scans
• No manual intervention needed
• Consistent scheduling

Scan Targets Explained

Supported Target Formats

Single IP Address:

192.168.1.100
10.0.0.50

CIDR Notation (Subnet):

192.168.1.0/24         # Scans 192.168.1.0-255 (254 hosts)
10.0.0.0/16            # Scans 10.0.0.0-255.255 (65534 hosts)
172.16.0.0/12          # Scans entire 172.16-31.x.x range

IP Range:

192.168.1.1-50         # Scans 192.168.1.1 to 192.168.1.50
10.0.0.1-10.0.0.100    # Scans across range

Multiple Targets:

192.168.1.1,192.168.1.2,192.168.1.3

Hostname/Domain:

scanme.nmap.org
example.com
server.local

Choosing Appropriate Targets

Development/Testing:

• Use scanme.nmap.org (official test target)
• Use your own isolated lab network
• Never scan public internet without permission

Internal Networks:

• Use CIDR notation for entire subnets
• Scan DMZ networks separately from internal
• Consider network segmentation in scan design

Understanding Report Contents

Report Structure

The generated report includes:

1. Executive Summary:

• Total hosts discovered
• Total services identified
• Total vulnerabilities found
• Severity breakdown (Critical, High, Medium, Low, Info)
• Scan date and time
• Target network

2. Overall Statistics:

• Visual dashboard with key metrics
• Severity distribution chart
• Quick risk assessment

3. Detailed Findings by Host: For each discovered host:

• IP address
• Hostname (if resolved)
• List of open ports and services
• Service details:
  • Port number and protocol
  • Service name (e.g., http, ssh, mysql)
  • Product (e.g., Apache, OpenSSH, MySQL)
  • Version (e.g., 2.4.41, 8.2p1, 5.7.33)
  • CPE identifier

4. Vulnerability Details: For each vulnerable service:

• CVE ID: Unique vulnerability identifier (e.g., CVE-2021-44228)
• Severity: CRITICAL / HIGH / MEDIUM / LOW / INFO
• CVSS Score: Numerical score (0.0-10.0)
• Published Date: When vulnerability was disclosed
• Description: Detailed vulnerability explanation
• References: Links to advisories, patches, exploits

5. Recommendations:

• Immediate actions (patch critical/high severity)
• Long-term improvements (security processes)
• Best practices

Vulnerability Severity Levels

CRITICAL (CVSS 9.0-10.0):

• Color: Red
• Characteristics: Remote code execution, full system compromise
• Action: Immediate patching required
• Examples: Log4Shell, EternalBlue, Heartbleed

HIGH (CVSS 7.0-8.9):

• Color: Orange
• Characteristics: Significant security impact, data exposure
• Action: Patch within days
• Examples: SQL injection, privilege escalation, authentication bypass

MEDIUM (CVSS 4.0-6.9):

• Color: Yellow
• Characteristics: Moderate security impact
• Action: Patch within weeks
• Examples: Information disclosure, denial of service, XSS

LOW (CVSS 0.1-3.9):

• Color: Green
• Characteristics: Minor security impact
• Action: Patch during regular maintenance
• Examples: Path disclosure, weak ciphers, verbose error messages

INFO (CVSS 0.0):

• Color: Blue
• Characteristics: No vulnerability found or informational
• Action: No action required, awareness only
• Examples: Service version detected, no known CVEs

Understanding CPE

CPE (Common Platform Enumeration):

• Standard naming scheme for IT products
• Used for CVE lookup in NVD database

Workflow CPE Handling:

• Nmap detects service and version
• Nmap provides CPE (if in database)
• Workflow uses CPE to query NVD API
• NVD returns CVEs associated with that CPE
• Special case: nginx vendor fixed from igor_sysoev to nginx

Working with Reports

Accessing HTML Report

Location:

/tmp/vulnerability_report_<timestamp>.html

Viewing:

• Open in web browser directly from n8n
• Click "11. Read Report for Output" node
• Download HTML file
• Open locally in any browser

Advantages:

• Interactive (clickable links)
• Searchable text
• Easy to edit/customize
• Smaller file size

Accessing PDF Report

Location:

/tmp/vulnerability_report_<timestamp>.pdf

Password:

• Default: Almafa123456 (configured in "1. Set Parameters")
• Change in workflow before production use
• Required to open PDF

Opening PDF:

1. Receive PDF via Telegram or Email
2. Open with PDF reader (Adobe, Foxit, Browser)
3. Enter password when prompted
4. View, print, or share

Advantages:

• Professional appearance
• Print-optimized formatting
• Password protection
• Portable (works anywhere)
• Preserves formatting

Report Customization

Change Report Title:

1. Open "8. Prepare Report Structure" node
2. Find metadata object
3. Edit title and subtitle fields

Customize Styling:

1. Open "9. Generate HTML Report" node
2. Modify CSS in <style> section
3. Change colors, fonts, layout

Add Company Logo:

1. Edit HTML generation code
2. Add <img> tag in header section
3. Include base64-encoded logo or URL

Modify Recommendations:

1. Open "9. Generate HTML Report" node
2. Find <h2>Recommendations</h2> section
3. Edit recommendation text

Scanning Ethics and Legality

1. Authorization is Mandatory:

   • Never scan networks without explicit written permission
   • Unauthorized scanning is illegal in most jurisdictions
   • Can result in criminal charges and civil liability

2. Scope Definition:

   • Document approved scan scope
   • Exclude out-of-scope systems
   • Maintain scan authorization documents

3. Notification:

   • Inform network administrators before scans
   • Provide scan window and source IPs
   • Have emergency contact procedures

4. Safe Targets for Testing:

   • scanme.nmap.org: Official Nmap test server
   • Your own isolated lab network
   • Cloud instances you own
   • Explicitly authorized environments

Compliance Considerations

PCI DSS:

• Quarterly internal vulnerability scans required
• Scan all system components
• Re-scan after significant changes
• Document scan results

HIPAA:

• Regular vulnerability assessments required
• Risk analysis and management
• Document remediation efforts

ISO 27001:

• Vulnerability management process
• Regular technical vulnerability scans
• Document procedures

NIST Cybersecurity Framework:

• Identify vulnerabilities (DE.CM-8)
• Maintain inventory
• Implement vulnerability management

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License and Credits

Workflow:

• Created for n8n workflow automation
• Free for personal and commercial use
• Modify and distribute as needed
• No warranty provided

Dependencies:

• Nmap: GPL v2 - https://nmap.org
• nmap-helper: Open source - https://github.com/net-shaper/nmap-helper
• Prince XML: Commercial license required for production use - https://www.princexml.com
• NVD API: Public API by NIST - https://nvd.nist.gov

Third-Party Services:

• Telegram Bot API: https://core.telegram.org/bots/api
• SMTP: Standard email protocol

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Support

For Nmap issues:

• Documentation: https://nmap.org/book/
• Community: https://seclists.org/nmap-dev/

For NVD API issues:

• Status page: https://nvd.nist.gov
• Contact: https://nvd.nist.gov/general/contact

For Prince XML issues:

• Documentation: https://www.princexml.com/doc/
• Support: https://www.princexml.com/doc/help/

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Workflow Metadata

• External Dependencies: Nmap, nmap-helper, Prince XML, NVD API
• License: Open for modification and commercial use

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Security Disclaimer

This workflow is provided for legitimate security testing and vulnerability assessment purposes only. Users are solely responsible for ensuring they have proper authorization before scanning any network or system. Unauthorized network scanning is illegal and unethical. The authors assume no liability for misuse of this workflow or any damages resulting from its use. Always obtain written permission before conducting security assessments.