Cvss Score Extraction

{
  "VulnerabilityID": "CVE-2021-44906",
  "PkgName": "minimist",
  "Severity": "CRITICAL",
  "CVSS": {
    "nvd": {
      "V2Vector": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
      "V3Vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "V2Score": 7.5,
      "V3Score": 9.8
    },
    "ghsa": {
      "V3Vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "V3Score": 9.8
    }
  }
}

def get_cvss_score(vuln_data):
    """
    Extract CVSS v3 score from vulnerability data.
    Uses priority: NVD > GHSA > RedHat
    
    Args:
        vuln_data: Dictionary containing vulnerability information
        
    Returns:
        CVSS v3 score as float, or 'N/A' if not available
    """
    cvss = vuln_data.get('CVSS', {})
    
    # Priority 1: NVD (National Vulnerability Database)
    if 'nvd' in cvss:
        score = cvss['nvd'].get('V3Score')
        if score is not None:
            return score
    
    # Priority 2: GHSA (GitHub Security Advisory)
    if 'ghsa' in cvss:
        score = cvss['ghsa'].get('V3Score')
        if score is not None:
            return score
    
    # Priority 3: RedHat
    if 'redhat' in cvss:
        score = cvss['redhat'].get('V3Score')
        if score is not None:
            return score
    
    # No score available
    return 'N/A'

def get_cvss_score_with_fallback(vuln_data):
    """
    Extract CVSS score with v2 fallback.
    Priority: NVD v3 > GHSA v3 > RedHat v3 > NVD v2 > N/A
    """
    cvss = vuln_data.get('CVSS', {})
    
    # Try v3 scores first
    for source in ['nvd', 'ghsa', 'redhat']:
        if source in cvss:
            v3_score = cvss[source].get('V3Score')
            if v3_score is not None:
                return {'score': v3_score, 'version': 'v3', 'source': source}
    
    # Fallback to v2 if v3 not available
    if 'nvd' in cvss:
        v2_score = cvss['nvd'].get('V2Score')
        if v2_score is not None:
            return {'score': v2_score, 'version': 'v2', 'source': 'nvd'}
    
    return {'score': 'N/A', 'version': None, 'source': None}

import json

def parse_vulnerabilities(json_file):
    """Parse Trivy JSON and extract vulnerabilities with CVSS scores."""
    with open(json_file, 'r') as f:
        data = json.load(f)
    
    vulnerabilities = []
    
    if 'Results' in data:
        for result in data['Results']:
            for vuln in result.get('Vulnerabilities', []):
                # Extract basic fields
                record = {
                    'Package': vuln.get('PkgName'),
                    'Version': vuln.get('InstalledVersion'),
                    'CVE_ID': vuln.get('VulnerabilityID'),
                    'Severity': vuln.get('Severity'),
                    'CVSS_Score': get_cvss_score(vuln),  # Use extraction function
                    'Fixed_Version': vuln.get('FixedVersion', 'N/A'),
                    'Title': vuln.get('Title', 'No description')
                }
                vulnerabilities.append(record)
    
    return vulnerabilities

cvss_score = get_cvss_score(vuln)
# Returns: 9.8 or 'N/A'

cvss_info = get_cvss_score_with_fallback(vuln)
# Returns: {'score': 9.8, 'version': 'v3', 'source': 'nvd'}

def is_high_severity(vuln_data, threshold=7.0):
    """Check if vulnerability meets severity threshold."""
    score = get_cvss_score(vuln_data)
    if score == 'N/A':
        # If no score, use severity label
        return vuln_data.get('Severity') in ['HIGH', 'CRITICAL']
    return score >= threshold

def safe_get_cvss_score(vuln_data):
    """Safely extract CVSS score with comprehensive error handling."""
    try:
        cvss = vuln_data.get('CVSS', {})
        
        # Validate cvss is a dictionary
        if not isinstance(cvss, dict):
            return 'N/A'
        
        for source in ['nvd', 'ghsa', 'redhat']:
            if source in cvss and isinstance(cvss[source], dict):
                score = cvss[source].get('V3Score')
                # Validate score is numeric
                if score is not None and isinstance(score, (int, float)):
                    return score
        
        return 'N/A'
    except (AttributeError, TypeError):
        return 'N/A'

import json

def get_cvss_score(vuln_data):
    """Extract CVSS v3 score with source priority."""
    cvss = vuln_data.get('CVSS', {})
    
    for source in ['nvd', 'ghsa', 'redhat']:
        if source in cvss:
            score = cvss[source].get('V3Score')
            if score is not None:
                return score
    
    return 'N/A'

def generate_report_with_cvss(json_file):
    """Generate vulnerability report with CVSS scores."""
    with open(json_file, 'r') as f:
        data = json.load(f)
    
    print(f"{'Package':<20} {'CVE ID':<20} {'CVSS':<8} {'Severity':<10}")
    print("-" * 60)
    
    if 'Results' in data:
        for result in data['Results']:
            for vuln in result.get('Vulnerabilities', []):
                pkg = vuln.get('PkgName', 'Unknown')
                cve = vuln.get('VulnerabilityID', 'N/A')
                cvss = get_cvss_score(vuln)
                severity = vuln.get('Severity', 'UNKNOWN')
                
                print(f"{pkg:<20} {cve:<20} {cvss:<8} {severity:<10}")

# Usage
generate_report_with_cvss('trivy_report.json')