security: fix path validation bypass, CORS restriction, cookie-import path check

- startsWith('/tmp') matched '/tmpevil' — now requires trailing slash
- CORS Access-Control-Allow-Origin changed from * to http://127.0.0.1:<port>
- cookie-import now validates file paths (was missing validateReadPath)
- 3 new tests for prefix collision and cookie-import path traversal

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

browse/src/cookie-picker-routes.ts

@@ -31,7 +31,7 @@ function jsonResponse(data: any, status = 200): Response {
     status,
     headers: {
       'Content-Type': 'application/json',
-      'Access-Control-Allow-Origin': '*',
+      'Access-Control-Allow-Origin': `http://127.0.0.1:${parseInt(url.port, 10) || 9400}`,
     },
   });
 }
@@ -54,7 +54,7 @@ export async function handleCookiePickerRoute(
     return new Response(null, {
       status: 204,
       headers: {
-        'Access-Control-Allow-Origin': '*',
+        'Access-Control-Allow-Origin': `http://127.0.0.1:${parseInt(url.port, 10) || 9400}`,
         'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
         'Access-Control-Allow-Headers': 'Content-Type',
       },

browse/src/meta-commands.ts

@@ -14,7 +14,7 @@ const SAFE_DIRECTORIES = ['/tmp', process.cwd()];
 
 function validateOutputPath(filePath: string): void {
   const resolved = path.resolve(filePath);
-  const isSafe = SAFE_DIRECTORIES.some(dir => resolved.startsWith(dir));
+  const isSafe = SAFE_DIRECTORIES.some(dir => resolved === dir || resolved.startsWith(dir + '/'));
   if (!isSafe) {
     throw new Error(`Path must be within: ${SAFE_DIRECTORIES.join(', ')}`);
   }

browse/src/read-commands.ts

@@ -16,7 +16,8 @@ const SAFE_DIRECTORIES = ['/tmp', process.cwd()];
 
 function validateReadPath(filePath: string): void {
   if (path.isAbsolute(filePath)) {
-    const isSafe = SAFE_DIRECTORIES.some(dir => path.resolve(filePath).startsWith(dir));
+    const resolved = path.resolve(filePath);
+    const isSafe = SAFE_DIRECTORIES.some(dir => resolved === dir || resolved.startsWith(dir + '/'));
     if (!isSafe) {
       throw new Error(`Absolute path must be within: ${SAFE_DIRECTORIES.join(', ')}`);
     }

browse/src/write-commands.ts

@@ -236,6 +236,17 @@ export async function handleWriteCommand(
     case 'cookie-import': {
       const filePath = args[0];
       if (!filePath) throw new Error('Usage: browse cookie-import <json-file>');
+      // Path validation — prevent reading arbitrary files
+      if (path.isAbsolute(filePath)) {
+        const safeDirs = ['/tmp', process.cwd()];
+        const resolved = path.resolve(filePath);
+        if (!safeDirs.some(dir => resolved === dir || resolved.startsWith(dir + '/'))) {
+          throw new Error(`Path must be within: ${safeDirs.join(', ')}`);
+        }
+      }
+      if (path.normalize(filePath).includes('..')) {
+        throw new Error('Path traversal sequences (..) are not allowed');
+      }
       if (!fs.existsSync(filePath)) throw new Error(`File not found: ${filePath}`);
       const raw = fs.readFileSync(filePath, 'utf-8');
       let cookies: any[];

browse/test/commands.test.ts

@@ -1495,4 +1495,32 @@ describe('Path traversal prevention', () => {
       try { fs.unlinkSync(tmpFile); } catch {}
     }
   });
+
+  test('screenshot rejects /tmpevil prefix collision', async () => {
+    await handleWriteCommand('goto', [baseUrl + '/basic.html'], bm);
+    try {
+      await handleMetaCommand('screenshot', ['/tmpevil/steal.png'], bm, () => {});
+      expect(true).toBe(false);
+    } catch (err: any) {
+      expect(err.message).toContain('Path must be within');
+    }
+  });
+
+  test('cookie-import rejects path traversal', async () => {
+    try {
+      await handleWriteCommand('cookie-import', ['../../etc/shadow'], bm);
+      expect(true).toBe(false);
+    } catch (err: any) {
+      expect(err.message).toContain('Path traversal');
+    }
+  });
+
+  test('cookie-import rejects absolute path outside safe dirs', async () => {
+    try {
+      await handleWriteCommand('cookie-import', ['/etc/passwd'], bm);
+      expect(true).toBe(false);
+    } catch (err: any) {
+      expect(err.message).toContain('Path must be within');
+    }
+  });
 });