tools: add avoid-prototype-pollution lint rule

lib/.eslintrc.yaml

@@ -160,6 +160,7 @@ rules:
     - name: SubtleCrypto
       message: Use `const { SubtleCrypto } = require('internal/crypto/webcrypto');` instead of the global.
   # Custom rules in tools/eslint-rules
+  node-core/avoid-prototype-pollution: error
   node-core/lowercase-name-for-primitive: error
   node-core/non-ascii-character: error
   node-core/no-array-destructuring: error

lib/internal/per_context/primordials.js

@@ -78,7 +78,7 @@ function copyPropsRenamed(src, dest, prefix) {
       copyAccessor(dest, prefix, newKey, desc);
     } else {
       const name = `${prefix}${newKey}`;
-      ReflectDefineProperty(dest, name, desc);
+      ReflectDefineProperty(dest, name, { __proto__: null, ...desc });
       if (varargsMethods.includes(name)) {
         ReflectDefineProperty(dest, `${name}Apply`, {
           __proto__: null,
@@ -105,7 +105,7 @@ function copyPropsRenamedBound(src, dest, prefix) {
       }
 
       const name = `${prefix}${newKey}`;
-      ReflectDefineProperty(dest, name, desc);
+      ReflectDefineProperty(dest, name, { __proto__: null, ...desc });
       if (varargsMethods.includes(name)) {
         ReflectDefineProperty(dest, `${name}Apply`, {
           __proto__: null,
@@ -129,7 +129,7 @@ function copyPrototype(src, dest, prefix) {
       }
 
       const name = `${prefix}${newKey}`;
-      ReflectDefineProperty(dest, name, desc);
+      ReflectDefineProperty(dest, name, { __proto__: null, ...desc });
       if (varargsMethods.includes(name)) {
         ReflectDefineProperty(dest, `${name}Apply`, {
           __proto__: null,
@@ -312,7 +312,7 @@ const copyProps = (src, dest) => {
       ReflectDefineProperty(
         dest,
         key,
-        ReflectGetOwnPropertyDescriptor(src, key));
+        { __proto__: null, ...ReflectGetOwnPropertyDescriptor(src, key) });
     }
   });
 };
@@ -340,7 +340,7 @@ const makeSafe = (unsafe, safe) => {
             return new SafeIterator(this);
           };
         }
-        ReflectDefineProperty(safe.prototype, key, desc);
+        ReflectDefineProperty(safe.prototype, key, { __proto__: null, ...desc });
       }
     });
   } else {

test/parallel/test-eslint-avoid-prototype-pollution.js

@@ -0,0 +1,147 @@
+'use strict';
+
+const common = require('../common');
+if ((!common.hasCrypto) || (!common.hasIntl)) {
+  common.skip('ESLint tests require crypto and Intl');
+}
+
+common.skipIfEslintMissing();
+
+const RuleTester = require('../../tools/node_modules/eslint').RuleTester;
+const rule = require('../../tools/eslint-rules/avoid-prototype-pollution');
+
+new RuleTester({
+  parserOptions: { ecmaVersion: 2022 },
+})
+  .run('property-descriptor-no-prototype-pollution', rule, {
+    valid: [
+      'ObjectDefineProperties({}, {})',
+      'ObjectCreate(null, {})',
+      'ObjectDefineProperties({}, { key })',
+      'ObjectCreate(null, { key })',
+      'ObjectDefineProperties({}, { ...spread })',
+      'ObjectCreate(null, { ...spread })',
+      'ObjectDefineProperties({}, { key: valueDescriptor })',
+      'ObjectCreate(null, { key: valueDescriptor })',
+      'ObjectDefineProperties({}, { key: { ...{}, __proto__: null } })',
+      'ObjectCreate(null, { key: { ...{}, __proto__: null } })',
+      'ObjectDefineProperties({}, { key: { __proto__: null } })',
+      'ObjectCreate(null, { key: { __proto__: null } })',
+      'ObjectDefineProperties({}, { key: { __proto__: null, enumerable: true } })',
+      'ObjectCreate(null, { key: { __proto__: null, enumerable: true } })',
+      'ObjectDefineProperties({}, { key: { "__proto__": null } })',
+      'ObjectCreate(null, { key: { "__proto__": null } })',
+      'ObjectDefineProperties({}, { key: { \'__proto__\': null } })',
+      'ObjectCreate(null, { key: { \'__proto__\': null } })',
+      'ObjectDefineProperty({}, "key", ObjectCreate(null))',
+      'ReflectDefineProperty({}, "key", ObjectCreate(null))',
+      'ObjectDefineProperty({}, "key", valueDescriptor)',
+      'ReflectDefineProperty({}, "key", valueDescriptor)',
+      'ObjectDefineProperty({}, "key", { __proto__: null })',
+      'ReflectDefineProperty({}, "key", { __proto__: null })',
+      'ObjectDefineProperty({}, "key", { __proto__: null, enumerable: true })',
+      'ReflectDefineProperty({}, "key", { __proto__: null, enumerable: true })',
+      'ObjectDefineProperty({}, "key", { "__proto__": null })',
+      'ReflectDefineProperty({}, "key", { "__proto__": null })',
+      'ObjectDefineProperty({}, "key", { \'__proto__\': null })',
+      'ReflectDefineProperty({}, "key", { \'__proto__\': null })',
+    ],
+    invalid: [
+      {
+        code: 'ObjectDefineProperties({}, ObjectGetOwnPropertyDescriptors({}))',
+        errors: [{ message: /prototype pollution/ }],
+      },
+      {
+        code: 'ObjectCreate(null, ObjectGetOwnPropertyDescriptors({}))',
+        errors: [{ message: /prototype pollution/ }],
+      },
+      {
+        code: 'ObjectDefineProperties({}, { key: {} })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectCreate(null, { key: {} })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperties({}, { key: { [void 0]: { ...{ __proto__: null } } } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectCreate(null, { key: { [void 0]: { ...{ __proto__: null } } } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperties({}, { key: { __proto__: Object.prototype } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectCreate(null, { key: { __proto__: Object.prototype } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperties({}, { key: { [`__proto__`]: null } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectCreate(null, { key: { [`__proto__`]: null } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperties({}, { key: { enumerable: true } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectCreate(null, { key: { enumerable: true } })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperty({}, "key", {})',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ReflectDefineProperty({}, "key", {})',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperty({}, "key", ObjectGetOwnPropertyDescriptor({}, "key"))',
+        errors: [{ message: /prototype pollution/ }],
+      },
+      {
+        code: 'ReflectDefineProperty({}, "key", ObjectGetOwnPropertyDescriptor({}, "key"))',
+        errors: [{ message: /prototype pollution/ }],
+      },
+      {
+        code: 'ObjectDefineProperty({}, "key", ReflectGetOwnPropertyDescriptor({}, "key"))',
+        errors: [{ message: /prototype pollution/ }],
+      },
+      {
+        code: 'ReflectDefineProperty({}, "key", ReflectGetOwnPropertyDescriptor({}, "key"))',
+        errors: [{ message: /prototype pollution/ }],
+      },
+      {
+        code: 'ObjectDefineProperty({}, "key", { __proto__: Object.prototype })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ReflectDefineProperty({}, "key", { __proto__: Object.prototype })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperty({}, "key", { [`__proto__`]: null })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ReflectDefineProperty({}, "key", { [`__proto__`]: null })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ObjectDefineProperty({}, "key", { enumerable: true })',
+        errors: [{ message: /null-prototype/ }],
+      },
+      {
+        code: 'ReflectDefineProperty({}, "key", { enumerable: true })',
+        errors: [{ message: /null-prototype/ }],
+      },
+    ]
+  });

tools/eslint-rules/avoid-prototype-pollution.js

@@ -0,0 +1,92 @@
+'use strict';
+
+function checkProperties(context, node) {
+  if (
+    node.type === 'CallExpression' &&
+    node.callee.name === 'ObjectGetOwnPropertyDescriptors'
+  ) {
+    context.report({
+      node,
+      message:
+        'Property descriptors inherits from the Object prototype, therefore are subject to prototype pollution',
+    });
+  }
+  if (node.type !== 'ObjectExpression') return;
+  for (const { key, value } of node.properties) {
+    if (
+      key != null && value != null &&
+      !(key.type === 'Identifier' && key.name === '__proto__') &&
+      !(key.type === 'Literal' && key.value === '__proto__')
+    ) {
+      checkPropertyDescriptor(context, value);
+    }
+  }
+}
+
+function checkPropertyDescriptor(context, node) {
+  if (
+    node.type === 'CallExpression' &&
+    (node.callee.name === 'ObjectGetOwnPropertyDescriptor' ||
+     node.callee.name === 'ReflectGetOwnPropertyDescriptor')
+  ) {
+    context.report({
+      node,
+      message:
+        'Property descriptors inherits from the Object prototype, therefore are subject to prototype pollution',
+      suggest: [{
+        desc: 'Wrap the property descriptor in a null-prototype object',
+        fix(fixer) {
+          return [
+            fixer.insertTextBefore(node, '{ __proto__: null,...'),
+            fixer.insertTextAfter(node, ' }'),
+          ];
+        },
+      }],
+    });
+  }
+  if (node.type !== 'ObjectExpression') return;
+
+  for (const { key, value } of node.properties) {
+    if (
+      key != null && value != null &&
+      ((key.type === 'Identifier' && key.name === '__proto__') ||
+        (key.type === 'Literal' && key.value === '__proto__')) &&
+      value.type === 'Literal' && value.value === null
+    ) {
+      return true;
+    }
+  }
+
+  context.report({
+    node,
+    message: 'Must use null-prototype object for property descriptors',
+  });
+}
+
+const CallExpression = 'ExpressionStatement[expression.type="CallExpression"]';
+module.exports = {
+  meta: { hasSuggestions: true },
+  create(context) {
+    return {
+      [`${CallExpression}[expression.callee.name=${/^(Object|Reflect)DefinePropert(ies|y)$/}]`](
+        node
+      ) {
+        switch (node.expression.callee.name) {
+          case 'ObjectDefineProperties':
+            checkProperties(context, node.expression.arguments[1]);
+            break;
+          case 'ReflectDefineProperty':
+          case 'ObjectDefineProperty':
+            checkPropertyDescriptor(context, node.expression.arguments[2]);
+            break;
+          default:
+            throw new Error('Unreachable');
+        }
+      },
+
+      [`${CallExpression}[expression.callee.name="ObjectCreate"][expression.arguments.length=2]`](node) {
+        checkProperties(context, node.expression.arguments[1]);
+      },
+    };
+  },
+};