/building-vulnerability-scanning-workflow

name: building-vulnerability-scanning-workflow
description: 'Builds a structured vulnerability scanning workflow using tools like Nessus, Qualys, and OpenVAS to discover,
  prioritize, and track remediation of security vulnerabilities across infrastructure. Use when SOC teams need to establish
  recurring vulnerability assessment processes, integrate scan results with SIEM alerting, and build remediation tracking
  dashboards.

  '
domain: cybersecurity
subdomain: soc-operations
tags:
- soc
- vulnerability-scanning
- nessus
- qualys
- openvas
- cvss
- remediation
- patch-management
version: '1.0'
author: mahipal
license: Apache-2.0
nist_csf:
- DE.CM-01
- DE.AE-02
- RS.MA-01
- DE.AE-06

Building Vulnerability Scanning Workflow

When to Use

Use this skill when:

• SOC teams need to establish or improve recurring vulnerability scanning programs
• Scan results require prioritization beyond raw CVSS scores using asset context and threat intelligence
• Vulnerability data must be integrated into SIEM for correlation with exploitation attempts
• Remediation tracking needs formalization with SLA-based dashboards and reporting

**Do not use** for penetration testing or active exploitation — vulnerability scanning identifies weaknesses, penetration testing validates exploitability.

Prerequisites

• Vulnerability scanner (Tenable Nessus Professional, Qualys VMDR, or OpenVAS/Greenbone)
• Asset inventory with criticality classifications (business-critical, standard, development)
• Network access from scanner to all target segments (agent-based or network scan)
• SIEM integration for scan result ingestion and correlation
• Patch management system (WSUS, SCCM, Intune) for remediation tracking

Workflow

Step 1: Define Scan Scope and Scheduling

Create scan policies covering all asset types:

**Nessus Scan Configuration (API):**

import requests

nessus_url = "https://nessus.company.com:8834"
headers = {"X-ApiKeys": f"accessKey={access_key};secretKey={secret_key}"}

# Create scan policy
policy = {
    "uuid": "advanced",
    "settings": {
        "name": "SOC Weekly Infrastructure Scan",
        "description": "Weekly credentialed scan of all server and workstation segments",
        "scanner_id": 1,
        "policy_id": 0,
        "text_targets": "10.0.0.0/16, 172.16.0.0/12",
        "launch": "WEEKLY",
        "starttime": "20240315T020000",
        "rrules": "FREQ=WEEKLY;INTERVAL=1;BYDAY=SA",
        "enabled": True
    },
    "credentials": {
        "add": {
            "Host": {
                "Windows": [{
                    "domain": "company.local",
                    "username": "nessus_svc",
                    "password": "SCAN_SERVICE_PASSWORD",
                    "auth_method": "Password"
                }],
                "SSH": [{
                    "username": "nessus_svc",
                    "private_key": "/path/to/nessus_key",
                    "auth_method": "public key"
                }]
            }
        }
    }
}

response = requests.post(f"{nessus_url}/scans", headers=headers, json=policy,
                         verify=not os.environ.get("SKIP_TLS_VERIFY", "").lower() == "true")  # Set SKIP_TLS_VERIFY=true for self-signed certs in lab environments
scan_id = response.json()["scan"]["id"]
print(f"Scan created: ID {scan_id}")

**Qualys VMDR Scan via API:**

import qualysapi

conn = qualysapi.connect(
    hostname="qualysapi.qualys.com",
    username="api_user",
    password="API_PASSWORD"
)

# Launch vulnerability scan
params = {
    "action": "launch",
    "scan_title": "Weekly_Infrastructure_Scan",
    "ip": "10.0.0.0/16",
    "option_id": "123456",  # Scan profile ID
    "iscanner_name": "Internal_Scanner_01",
    "priority": "0"
}

response = conn.request("/api/2.0/fo/scan/", params)
print(f"Scan launched: {response}")

Step 2: Process and Prioritize Scan Results

Download results and apply risk-based prioritization:

import requests
import csv

# Export Nessus results
response = requests.get(
    f"{nessus_url}/scans/{scan_id}/export",
    headers=headers,
    params={"format": "csv"},
    verify=not os.environ.get("SKIP_TLS_VERIFY", "").lower() == "true",  # Set SKIP_TLS_VERIFY=true for self-signed certs in lab environments
)

# Parse and prioritize
vulns = []
reader = csv.DictReader(response.text.splitlines())
for row in reader:
    cvss = float(row.get("CVSS v3.0 Base Score", 0))
    asset_criticality = get_asset_criticality(row["Host"])  # From asset inventory

    # Risk-based priority calculation
    risk_score = cvss * asset_criticality_multiplier(asset_criticality)

    # Boost score if actively exploited (check CISA KEV)
    if row.get("CVE") in cisa_kev_list:
        risk_score *= 1.5

    vulns.append({
        "host": row["Host"],
        "plugin_name": row["Name"],
        "severity": row["Risk"],
        "cvss": cvss,
        "cve": row.get("CVE", "N/A"),
        "risk_score": round(risk_score, 1),
        "asset_criticality": asset_criticality,
        "kev": row.get("CVE") in cisa_kev_list
    })

# Sort by risk score
vulns.sort(key=lambda x: x["risk_score"], reverse=True)

**CISA KEV (Known Exploited Vulnerabilities) Check:**

import requests

kev_response = requests.get(
    "https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json"
)
kev_data = kev_response.json()
cisa_kev_list = {v["cveID"] for v in kev_data["vulnerabilities"]}

# Check if vulnerability is actively exploited
def is_actively_exploited(cve_id):
    return cve_id in cisa_kev_list

Step 3: Define Remediation SLAs

Apply SLA-based remediation timelines:

| Priority | CVSS Range | Asset Type | SLA | Examples | |----------|-----------|------------|-----|---------| | **P1 Critical** | 9.0-10.0 + KEV | All assets | 24 hours | Log4Shell, EternalBlue on prod servers | | **P2 High** | 7.0-8.9 or 9.0+ non-KEV | Business-critical | 7 days | RCE without known exploit | | **P3 Mediu