run2-trivy-offline-scanning

name	run2_trivy-offline-scanning
description	Use Trivy vulnerability scanner in offline mode to scan dependency lock files and produce JSON vulnerability reports without internet access.

Trivy Offline Vulnerability Scanning (Round 2)

Environment Details

• Trivy binary: /usr/bin/trivy (version 0.69.3)
• Database cache: /root/trivy-cache/ (contains db/trivy.db and db/metadata.json)
• DB updated: 2026-01-21 (may be outdated — scan results reflect DB date)

Key Command

trivy fs /root/package-lock.json \
  --format json \
  --output /root/trivy_report.json \
  --scanners vuln \
  --skip-db-update \
  --offline-scan \
  --cache-dir /root/trivy-cache

Important Flags

Flag	Purpose
fs <file>	Scan a dependency lock file directly
--skip-db-update	Don't fetch updated DB (offline requirement)
--offline-scan	Disable all network calls
--cache-dir	Point to offline DB location
--scanners vuln	Only vulnerability scanning (skip misconfig)

Behavior Notes

• Trivy by default suppresses dev dependencies — use --include-dev-deps if needed
• Output goes to the file specified by --output; stdout shows only progress logs
• Non-zero exit code indicates scan failure (not just vulnerability presence)

Python Wrapper

import subprocess, sys, os

def run_trivy_scan(target='/root/package-lock.json',
                   output='/root/trivy_report.json',
                   cache_dir='/root/trivy-cache'):
    db_path = os.path.join(cache_dir, 'db', 'trivy.db')
    if not os.path.exists(db_path):
        print(f"[!] DB not found at {db_path}")
        sys.exit(1)

    cmd = [
        'trivy', 'fs', target,
        '--format', 'json',
        '--output', output,
        '--scanners', 'vuln',
        '--skip-db-update',
        '--offline-scan',
        '--cache-dir', cache_dir
    ]
    result = subprocess.run(cmd, capture_output=True, text=True)
    if result.returncode != 0:
        print(result.stderr)
        sys.exit(1)
    print(f"[+] Scan complete: {output}")
    return output

JSON Output Structure

{
  "Results": [
    {
      "Target": "package-lock.json",
      "Class": "lang-pkgs",
      "Type": "npm",
      "Vulnerabilities": [
        {
          "VulnerabilityID": "CVE-2024-29415",
          "PkgName": "ip",
          "InstalledVersion": "2.0.0",
          "FixedVersion": "",        // Empty string = no fix; use 'N/A'
          "Severity": "HIGH",
          "Title": "node-ip: Incomplete fix for CVE-2023-42282",
          "PrimaryURL": "https://avd.aquasec.com/nvd/cve-2024-29415",
          "CVSS": {
            "ghsa":    
                
          
        
      
    
  

Gotchas

• FixedVersion can be None OR an empty string "" — handle both as 'N/A'
• Vulnerabilities key may be null (not just missing) — use or [] not just .get()
• Multiple fix versions are comma-separated in a single string: "7.5.2, 6.3.1, 5.7.2"