fix(cursor): validate blocking hook input

.cursor/hooks/adapter.js

@@ -15,11 +15,12 @@ const STOP_FORMAT_TYPECHECK_TIMEOUT_HEADROOM_MS = 15000;
 
 function readStdin(options = {}) {
   return new Promise((resolve) => {
+    const stream = options.stream || process.stdin;
     let data = '';
     let dataBytes = 0;
     let truncated = false;
-    process.stdin.setEncoding('utf8');
-    process.stdin.on('data', chunk => {
+    stream.setEncoding('utf8');
+    stream.on('data', chunk => {
       const chunkBytes = Buffer.byteLength(chunk, 'utf8');
       if (truncated || dataBytes + chunkBytes > MAX_STDIN_BYTES) {
         truncated = true;
@@ -28,7 +29,7 @@ function readStdin(options = {}) {
       data += chunk;
       dataBytes += chunkBytes;
     });
-    process.stdin.on('end', () => {
+    stream.on('end', () => {
       if (truncated) {
         if (options.includeMetadata !== true) {
           process.stderr.write(
@@ -36,18 +37,18 @@ function readStdin(options = {}) {
           );
         }
         resolve(options.includeMetadata === true
-          ? { raw: '', truncated: true }
+          ? { raw: '', truncated: true, readError: false }
           : '');
         return;
       }
       resolve(options.includeMetadata === true
-        ? { raw: data, truncated: false }
+        ? { raw: data, truncated: false, readError: false }
         : data);
     });
-    process.stdin.on('error', error => {
+    stream.on('error', error => {
       process.stderr.write(`[Cursor Hook] stdin read failed: ${error.message}\n`);
       resolve(options.includeMetadata === true
-        ? { raw: '', truncated: false }
+        ? { raw: '', truncated: false, readError: true }
         : '');
     });
   });

.cursor/hooks/before-read-file.js

@@ -7,7 +7,8 @@ readStdin().then(raw => {
   }
   try {
     const input = JSON.parse(raw);
-    const filePath = input.file_path || input.path || input.file || '';
+    const filePath = [input.file_path, input.path, input.file]
+      .find(value => typeof value === 'string' && value.trim()) || '';
     if (/\.(env|key|pem)$|\.env\.|credentials|secret/i.test(filePath)) {
       console.error('[ECC] WARNING: Reading sensitive file: ' + filePath);
       console.error('[ECC] Ensure this data is not exposed in outputs');

.cursor/hooks/before-shell-execution.js

@@ -7,8 +7,8 @@ const {
 } = require('./adapter');
 
 readStdin({ includeMetadata: true })
-  .then(({ raw, truncated }) => {
-    if (truncated) {
+  .then(({ raw, truncated, readError }) => {
+    if (truncated || readError) {
       const hasBlockingGuard = (
         hookEnabled('pre:bash:block-no-verify', ['minimal', 'standard', 'strict'])
         || (
@@ -17,12 +17,14 @@ readStdin({ includeMetadata: true })
         )
       );
       if (hasBlockingGuard) {
-        console.error(
-          '[Cursor Hook] stdin exceeded the safety limit; blocking beforeShellExecution'
-        );
+        console.error(truncated
+          ? '[Cursor Hook] stdin exceeded the safety limit; blocking beforeShellExecution'
+          : '[Cursor Hook] stdin read failed; blocking beforeShellExecution');
         process.exit(2);
       }
-      console.error('[Cursor Hook] stdin exceeded the safety limit; suppressing truncated input');
+      console.error(truncated
+        ? '[Cursor Hook] stdin exceeded the safety limit; suppressing truncated input'
+        : '[Cursor Hook] stdin read failed; suppressing untrusted input');
       return;
     }
 

.cursor/hooks/before-tab-file-read.js

@@ -1,17 +1,20 @@
 #!/usr/bin/env node
 const { readStdin, hookEnabled } = require('./adapter');
-readStdin({ includeMetadata: true }).then(({ raw, truncated }) => {
+readStdin({ includeMetadata: true }).then(({ raw, truncated, readError }) => {
   if (!hookEnabled('pre:tab-read:sensitive-file-block', ['minimal', 'standard', 'strict'])) {
     process.stdout.write(raw);
     return;
   }
-  if (truncated) {
-    console.error('[Cursor Hook] stdin exceeded the safety limit; blocking beforeTabFileRead');
+  if (truncated || readError) {
+    console.error(truncated
+      ? '[Cursor Hook] stdin exceeded the safety limit; blocking beforeTabFileRead'
+      : '[Cursor Hook] stdin read failed; blocking beforeTabFileRead');
     process.exit(2);
   }
   try {
     const input = JSON.parse(raw);
-    const filePath = input.file_path || input.path || input.file || '';
+    const filePath = [input.file_path, input.path, input.file]
+      .find(value => typeof value === 'string' && value.trim()) || '';
     if (/\.(env|key|pem)$|\.env\.|credentials|secret/i.test(filePath)) {
       console.error('[ECC] BLOCKED: Tab cannot read sensitive file: ' + filePath);
       process.exit(2);

tests/hooks/cursor-hook-dispatchers.test.js

@@ -287,6 +287,17 @@ if (test('Cursor-sensitive file hooks recognize the official file_path field', (
   assert.match(blocked.stderr, /BLOCKED/);
 })) passed++; else failed++;
 
+if (test('invalid path field types cannot shadow a valid string fallback', () => {
+  const input = { file_path: {}, path: '.env' };
+  const warning = runHook(BEFORE_READ, input);
+  assert.strictEqual(warning.status, 0, warning.stderr);
+  assert.match(warning.stderr, /Reading sensitive file/);
+
+  const blocked = runHook(BEFORE_TAB_READ, input);
+  assert.strictEqual(blocked.status, 2, blocked.stderr);
+  assert.match(blocked.stderr, /BLOCKED/);
+})) passed++; else failed++;
+
 if (test('Cursor-native audit hooks stay disabled in the minimal profile', () => {
   const cases = [
     [BEFORE_MCP, { server: 'example', tool: 'read' }],
@@ -661,6 +672,27 @@ if (test('oversized beforeTabFileRead input fails closed', () => {
   assert.match(result.stderr, /stdin exceeded.*blocking/i);
 })) passed++; else failed++;
 
+if (test('readStdin exposes stream failures to blocking dispatchers', () => {
+  const probe = [
+    "const { EventEmitter } = require('events');",
+    `const { readStdin } = require(${JSON.stringify(path.join(REPO_ROOT, '.cursor', 'hooks', 'adapter.js'))});`,
+    "const stream = new EventEmitter();",
+    "stream.setEncoding = () => {};",
+    "readStdin({ includeMetadata: true, stream }).then(result => process.stdout.write(JSON.stringify(result)));",
+    "setImmediate(() => stream.emit('error', new Error('synthetic read failure')));",
+  ].join('\n');
+  const result = spawnSync(process.execPath, ['-e', probe], {
+    encoding: 'utf8',
+    timeout: 5000,
+  });
+  assert.strictEqual(result.status, 0, result.stderr);
+  assert.deepStrictEqual(JSON.parse(result.stdout), {
+    raw: '',
+    truncated: false,
+    readError: true,
+  });
+})) passed++; else failed++;
+
 console.log('-'.repeat(55));
 console.log(`Passed: ${passed}`);
 console.log(`Failed: ${failed}`);