cve_lookup
Look up detailed CVE vulnerability information from the National Vulnerability Database. Get CVSS scores, descriptions, references, and weakness details to understand security implications.
Instructions
Lookup CVE vulnerability information from the National Vulnerability Database
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| cve_id | Yes | Lookup detailed information about a CVE (Common Vulnerabilities and Exposures) from the National Vulnerability Database. Provide a CVE ID in the format CVE-YYYY-NNNN (e.g., CVE-2021-44228 for Log4Shell). Returns comprehensive vulnerability details including CVSS scores, descriptions, references, and associated weaknesses to help engineers understand security implications. |
Implementation Reference
- The core handler function that takes a CVE ID, validates it, queries the NVD API, extracts vulnerability details including descriptions, CVSS scores, weaknesses, and references, then returns a formatted markdown TextContent report.
async def lookup_cve( cve_id: str, ) -> List[types.TextContent | types.ImageContent | types.EmbeddedResource]: """ Lookup CVE vulnerability information from the National Vulnerability Database (NVD). Provides detailed information about Common Vulnerabilities and Exposures. Args: cve_id: CVE identifier in format CVE-YYYY-NNNN Returns: List of content containing CVE information or error messages """ # Clean up CVE ID format cve_id = cve_id.upper().strip() if not cve_id.startswith("CVE-"): cve_id = f"CVE-{cve_id}" # Validate CVE ID format (CVE-YYYY-NNNN) if not re.match(r"^CVE-\d{4}-\d{4,}$", cve_id): return [ types.TextContent( type="text", text=f"Error: Invalid CVE ID format. Expected format: CVE-YYYY-NNNN (e.g., CVE-2021-44228). Got: {cve_id}", ) ] headers = {"User-Agent": "MCP CVE Lookup Tool v1.0"} try: timeout = httpx.Timeout(15.0, connect=10.0) async with httpx.AsyncClient( follow_redirects=True, headers=headers, timeout=timeout ) as client: # NVD API 2.0 endpoint url = f"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId={cve_id}" response = await client.get(url) response.raise_for_status() data = response.json() if data.get("totalResults", 0) == 0: return [ types.TextContent( type="text", text=f"CVE {cve_id} not found in the National Vulnerability Database.", ) ] cve_item = data["vulnerabilities"][0]["cve"] # Extract key information cve_info = { "id": cve_item["id"], "published": cve_item.get("published", "Unknown"), "lastModified": cve_item.get("lastModified", "Unknown"), "descriptions": [], "cvss_scores": [], "references": [], "configurations": [], "weaknesses": [], } # Get descriptions for desc in cve_item.get("descriptions", []): if desc.get("lang") == "en": cve_info["descriptions"].append(desc.get("value", "")) # Get CVSS scores metrics = cve_item.get("metrics", {}) # CVSS 3.1 if "cvssMetricV31" in metrics: for metric in metrics["cvssMetricV31"]: cvss_data = metric.get("cvssData", {}) cve_info["cvss_scores"].append( { "version": "3.1", "score": cvss_data.get("baseScore", "N/A"), "severity": cvss_data.get("baseSeverity", "N/A"), "vector": cvss_data.get("vectorString", "N/A"), "source": metric.get("source", "N/A"), } ) # CVSS 3.0 if "cvssMetricV30" in metrics: for metric in metrics["cvssMetricV30"]: cvss_data = metric.get("cvssData", {}) cve_info["cvss_scores"].append( { "version": "3.0", "score": cvss_data.get("baseScore", "N/A"), "severity": cvss_data.get("baseSeverity", "N/A"), "vector": cvss_data.get("vectorString", "N/A"), "source": metric.get("source", "N/A"), } ) # CVSS 2.0 if "cvssMetricV2" in metrics: for metric in metrics["cvssMetricV2"]: cvss_data = metric.get("cvssData", {}) cve_info["cvss_scores"].append( { "version": "2.0", "score": cvss_data.get("baseScore", "N/A"), "severity": cvss_data.get("baseSeverity", "N/A"), "vector": cvss_data.get("vectorString", "N/A"), "source": metric.get("source", "N/A"), } ) # Get references for ref in cve_item.get("references", []): cve_info["references"].append( { "url": ref.get("url", ""), "source": ref.get("source", ""), "tags": ref.get("tags", []), } ) # Get weaknesses (CWE) for weakness in cve_item.get("weaknesses", []): for desc in weakness.get("description", []): if desc.get("lang") == "en": cve_info["weaknesses"].append(desc.get("value", "")) # Format the response result = f"🔍 **CVE Vulnerability Report: {cve_info['id']}**\n\n" # Published/Modified dates result += "📅 **Timeline:**\n" result += f" • Published: {cve_info['published']}\n" result += f" • Last Modified: {cve_info['lastModified']}\n\n" # Description if cve_info["descriptions"]: result += "📝 **Description:**\n" for desc in cve_info["descriptions"]: result += f" {desc}\n\n" # CVSS Scores if cve_info["cvss_scores"]: result += "⚠️ **CVSS Scores:**\n" for score in cve_info["cvss_scores"]: result += f" • CVSS {score['version']}: {score['score']} ({score['severity']})\n" result += f" Vector: {score['vector']}\n" result += f" Source: {score['source']}\n" result += "\n" # Weaknesses (CWE) if cve_info["weaknesses"]: result += "🛡️ **Weaknesses (CWE):**\n" for weakness in cve_info["weaknesses"]: result += f" • {weakness}\n" result += "\n" # References if cve_info["references"]: result += "🔗 **References:**\n" for ref in cve_info["references"][:10]: # Limit to first 10 references tags = ", ".join(ref["tags"]) if ref["tags"] else "General" result += f" • [{ref['source']}] {ref['url']}\n" result += f" Tags: {tags}\n" if len(cve_info["references"]) > 10: result += f" ... and {len(cve_info['references']) - 10} more references\n" result += "\n" result += "📊 **Data Source:** National Vulnerability Database (NVD)\n" result += f"🌐 **Official CVE URL:** https://cve.mitre.org/cgi-bin/cvename.cgi?name={cve_info['id']}" return [types.TextContent(type="text", text=result)] except httpx.TimeoutException: return [ types.TextContent( type="text", text="Error: Request timed out while fetching CVE information from NVD.", ) ] except httpx.HTTPStatusError as e: if e.response.status_code == 404: return [ types.TextContent( type="text", text=f"CVE {cve_id} not found in the National Vulnerability Database.", ) ] return [ types.TextContent( type="text", text=f"Error: HTTP {e.response.status_code} error while fetching CVE data.", ) ] except json.JSONDecodeError: return [ types.TextContent( type="text", text="Error: Invalid JSON response from NVD API." ) ] except Exception as e: return [ types.TextContent( type="text", text=f"Error: Failed to fetch CVE information: {str(e)}", ) ] - mcp_simple_tool/server.py:164-176 (schema)The JSON schema definition for the cve_lookup tool's input, requiring a 'cve_id' string parameter with detailed usage description.
name="cve_lookup", description="Lookup CVE vulnerability information from the National Vulnerability Database", inputSchema={ "type": "object", "required": ["cve_id"], "properties": { "cve_id": { "type": "string", "description": cve_description, } }, }, ), - mcp_simple_tool/server.py:90-98 (registration)Registration and dispatch logic in the @app.call_tool() handler that routes 'cve_lookup' calls to the lookup_cve function after input validation.
if name == "cve_lookup": if "cve_id" not in arguments: return [ types.TextContent( type="text", text="Error: Missing required argument 'cve_id'" ) ] return await lookup_cve(arguments["cve_id"]) elif name == "package_vulnerability_check":