Local Explorer MCP

/** * RACE CONDITION (TOCTOU) ATTACK TESTS * Time-Of-Check-Time-Of-Use vulnerabilities */ import { describe, it, expect, beforeAll, afterAll } from 'vitest'; import { validateExecutionContext } from '../../src/security/executionContextValidator.js'; import { PathValidator } from '../../src/security/pathValidator.js'; import fs from 'fs'; import path from 'path'; describe('RACE CONDITION ATTACKS (TOCTOU)', () => { const workspace = '/Users/guybary/path_validator_toctou_test'; let validator: PathValidator; beforeAll(() => { fs.mkdirSync(workspace, { recursive: true }); validator = new PathValidator(workspace); }); afterAll(() => { try { // Cleanup const files = fs.readdirSync(workspace); files.forEach(file => { const filePath = path.join(workspace, file); try { if (fs.lstatSync(filePath).isSymbolicLink()) { fs.unlinkSync(filePath); } else if (fs.statSync(filePath).isDirectory()) { fs.rmdirSync(filePath); } else { fs.unlinkSync(filePath); } } catch { // Ignore cleanup errors } }); fs.rmdirSync(workspace); } catch { // Ignore cleanup errors } }); it('ATTACK: Swap file after validation (classic TOCTOU)', async () => { const testFile = path.join(workspace, 'toctou_test.txt'); // Step 1: Create legitimate file fs.writeFileSync(testFile, 'safe content'); console.log('\n🔴 ATTACK: TOCTOU - Swap file after validation'); // Step 2: Validate (TIME OF CHECK) const result1 = validator.validate(testFile); console.log(` Validation 1: ${result1.isValid ? 'PASS' : 'FAIL'}`); expect(result1.isValid).toBe(true); // Step 3: Swap with symlink (ATTACKER SWAPS FILE) fs.unlinkSync(testFile); fs.symlinkSync('/etc/passwd', testFile); // Step 4: Use the file (TIME OF USE) // The validator should catch this if it validates again const result2 = validator.validate(testFile); console.log(` Validation 2 (after swap): ${result2.isValid ? '❌ BYPASSED' : '✅ BLOCKED'}`); console.log(` Error: ${result2.error || 'none'}`); // The validator uses fs.realpathSync() which should catch this expect(result2.isValid).toBe(false); // Cleanup fs.unlinkSync(testFile); }); it('ATTACK: Race condition with directory swap', async () => { const testDir = path.join(workspace, 'toctou_dir'); // Step 1: Create legitimate directory fs.mkdirSync(testDir); console.log('\n🔴 ATTACK: TOCTOU - Directory swap'); // Validate const result1 = validator.validate(testDir); console.log(` Validation 1: ${result1.isValid ? 'PASS' : 'FAIL'}`); expect(result1.isValid).toBe(true); // Swap directory with symlink fs.rmdirSync(testDir); fs.symlinkSync('/etc', testDir); // Validate again const result2 = validator.validate(testDir); console.log(` Validation 2 (after swap): ${result2.isValid ? '❌ BYPASSED' : '✅ BLOCKED'}`); expect(result2.isValid).toBe(false); // Cleanup fs.unlinkSync(testDir); }); it('SECURITY TEST: PathValidator uses realpath (safe against TOCTOU)', () => { console.log('\n🔍 Checking if PathValidator uses fs.realpathSync():'); // Read the source code to verify const source = fs.readFileSync( path.join(__dirname, '../../src/security/pathValidator.ts'), 'utf-8' ); const usesRealpath = source.includes('realpathSync'); console.log(` Uses fs.realpathSync(): ${usesRealpath ? '✅ YES - Protected' : '❌ NO - Vulnerable'}`); expect(usesRealpath).toBe(true); }); it('MITIGATION: Validate just before use (recommended pattern)', () => { console.log('\n✅ RECOMMENDED: Always validate immediately before use'); console.log(' Pattern: validate() -> use file immediately'); console.log(' Pattern: Do NOT store validation results for later use'); console.log(' Pattern: Re-validate if time has passed'); expect(true).toBe(true); }); it('TOCTOU FIX: validator.validate does not crash if path disappears', () => { const tmp = path.join(workspace, 'maybe-missing'); try { fs.rmSync(tmp, { recursive: true, force: true }); } catch { /* ignore */ } const res = validator.validate(tmp); expect(res.isValid).toBe(true); expect(res.sanitizedPath).toBeDefined(); }); it('TOCTOU FIX: executionContextValidator allows non-existent cwd within workspace', () => { const tmp = path.join(workspace, 'missing-cwd'); try { fs.rmSync(tmp, { recursive: true, force: true }); } catch { /* ignore */ } const res = validateExecutionContext(tmp, workspace); expect(res.isValid).toBe(true); expect(res.sanitizedPath).toBeDefined(); }); });