fix: protected fields exposed via LiveQuery; this removes protected fields from the client response; this may be a breaking change if your app is currently expecting to receive these protected fields ([GHSA-crrq-vr9j-fxxh](https://github.com/parse-community/parse-server/security/advisories/GHSA-crrq-vr9j-fxxh)) (https://github.com/parse-community/parse-server/pull/8074) (#8073)

spec/ParseLiveQuery.spec.js

@@ -1066,6 +1066,52 @@ describe('ParseLiveQuery', function () {
     }
   });
 
+  it('should strip out protected fields', async () => {
+    await reconfigureServer({
+      liveQuery: { classNames: ['Test'] },
+      startLiveQueryServer: true,
+    });
+    const obj1 = new Parse.Object('Test');
+    obj1.set('foo', 'foo');
+    obj1.set('bar', 'bar');
+    obj1.set('qux', 'qux');
+    await obj1.save();
+    const config = Config.get(Parse.applicationId);
+    const schemaController = await config.database.loadSchema();
+    await schemaController.updateClass(
+      'Test',
+      {},
+      {
+        get: { '*': true },
+        find: { '*': true },
+        update: { '*': true },
+        protectedFields: {
+          '*': ['foo'],
+        },
+      }
+    );
+    const object = await obj1.fetch();
+    expect(object.get('foo')).toBe(undefined);
+    expect(object.get('bar')).toBeDefined();
+    expect(object.get('qux')).toBeDefined();
+
+    const subscription = await new Parse.Query('Test').subscribe();
+    await Promise.all([
+      new Promise(resolve => {
+        subscription.on('update', (obj, original) => {
+          expect(obj.get('foo')).toBe(undefined);
+          expect(obj.get('bar')).toBeDefined();
+          expect(obj.get('qux')).toBeDefined();
+          expect(original.get('foo')).toBe(undefined);
+          expect(original.get('bar')).toBeDefined();
+          expect(original.get('qux')).toBeDefined();
+          resolve();
+        });
+      }),
+      obj1.save({ foo: 'abc' }),
+    ]);
+  });
+
   afterEach(async function (done) {
     const client = await Parse.CoreManager.getLiveQueryController().getDefaultLiveQueryClient();
     client.close();

src/Controllers/DatabaseController.js

@@ -127,7 +127,7 @@ const filterSensitiveData = (
   aclGroup: any[],
   auth: any,
   operation: any,
-  schema: SchemaController.SchemaController,
+  schema: SchemaController.SchemaController | any,
   className: string,
   protectedFields: null | Array<any>,
   object: any
@@ -136,7 +136,8 @@ const filterSensitiveData = (
   if (auth && auth.user) userId = auth.user.id;
 
   // replace protectedFields when using pointer-permissions
-  const perms = schema.getClassLevelPermissions(className);
+  const perms =
+    schema && schema.getClassLevelPermissions ? schema.getClassLevelPermissions(className) : {};
   if (perms) {
     const isReadOperation = ['get', 'find'].indexOf(operation) > -1;
 
@@ -1533,14 +1534,17 @@ class DatabaseController {
   }
 
   addProtectedFields(
-    schema: SchemaController.SchemaController,
+    schema: SchemaController.SchemaController | any,
     className: string,
     query: any = {},
     aclGroup: any[] = [],
     auth: any = {},
     queryOptions: FullQueryOptions = {}
   ): null | string[] {
-    const perms = schema.getClassLevelPermissions(className);
+    const perms =
+      schema && schema.getClassLevelPermissions
+        ? schema.getClassLevelPermissions(className)
+        : schema;
     if (!perms) return null;
 
     const protectedFields = perms.protectedFields;
@@ -1806,8 +1810,10 @@ class DatabaseController {
   }
 
   static _validateQuery: any => void;
+  static filterSensitiveData: (boolean, any[], any, any, any, string, any[], any) => void;
 }
 
 module.exports = DatabaseController;
 // Expose validateQuery for tests
 module.exports._validateQuery = validateQuery;
+module.exports.filterSensitiveData = filterSensitiveData;

src/LiveQuery/ParseCloudCodePublisher.js

@@ -33,6 +33,9 @@ class ParseCloudCodePublisher {
     if (request.original) {
       message.originalParseObject = request.original._toFullJSON();
     }
+    if (request.classLevelPermissions) {
+      message.classLevelPermissions = request.classLevelPermissions;
+    }
     this.parsePublisher.publish(type, JSON.stringify(message));
   }
 }

src/LiveQuery/ParseLiveQueryServer.js

@@ -10,11 +10,18 @@ import { ParsePubSub } from './ParsePubSub';
 import SchemaController from '../Controllers/SchemaController';
 import _ from 'lodash';
 import { v4 as uuidv4 } from 'uuid';
-import { runLiveQueryEventHandlers, getTrigger, runTrigger, resolveError, toJSONwithObjects } from '../triggers';
+import {
+  runLiveQueryEventHandlers,
+  getTrigger,
+  runTrigger,
+  resolveError,
+  toJSONwithObjects,
+} from '../triggers';
 import { getAuthForSessionToken, Auth } from '../Auth';
-import { getCacheController } from '../Controllers';
+import { getCacheController, getDatabaseController } from '../Controllers';
 import LRU from 'lru-cache';
 import UserRouter from '../Routers/UsersRouter';
+import DatabaseController from '../Controllers/DatabaseController';
 
 class ParseLiveQueryServer {
   clients: Map;
@@ -185,14 +192,14 @@ class ParseLiveQueryServer {
             if (res.object && typeof res.object.toJSON === 'function') {
               deletedParseObject = toJSONwithObjects(res.object, res.object.className || className);
             }
-            if (
+            await this._filterSensitiveData(
-              (deletedParseObject.className === '_User' ||
+              classLevelPermissions,
-                deletedParseObject.className === '_Session') &&
+              res,
-              !client.hasMasterKey
+              client,
-            ) {
+              requestId,
-              delete deletedParseObject.sessionToken;
+              op,
-              delete deletedParseObject.authData;
+              subscription.query
-            }
+            );
             client.pushDelete(requestId, deletedParseObject);
           } catch (e) {
             const error = resolveError(e);
@@ -339,16 +346,14 @@ class ParseLiveQueryServer {
                 res.original.className || className
               );
             }
-            if (
+            await this._filterSensitiveData(
-              (currentParseObject.className === '_User' ||
+              classLevelPermissions,
-                currentParseObject.className === '_Session') &&
+              res,
-              !client.hasMasterKey
+              client,
-            ) {
+              requestId,
-              delete currentParseObject.sessionToken;
+              op,
-              delete originalParseObject?.sessionToken;
+              subscription.query
-              delete currentParseObject.authData;
+            );
-              delete originalParseObject?.authData;
-            }
             const functionName = 'push' + res.event.charAt(0).toUpperCase() + res.event.slice(1);
             if (client[functionName]) {
               client[functionName](requestId, currentParseObject, originalParseObject);
@@ -540,6 +545,54 @@ class ParseLiveQueryServer {
     // return rolesQuery.find({useMasterKey:true});
   }
 
+  async _filterSensitiveData(
+    classLevelPermissions: ?any,
+    res: any,
+    client: any,
+    requestId: number,
+    op: string,
+    query: any
+  ) {
+    const subscriptionInfo = client.getSubscriptionInfo(requestId);
+    const aclGroup = ['*'];
+    let clientAuth;
+    if (typeof subscriptionInfo !== 'undefined') {
+      const { userId, auth } = await this.getAuthForSessionToken(subscriptionInfo.sessionToken);
+      if (userId) {
+        aclGroup.push(userId);
+      }
+      clientAuth = auth;
+    }
+    const filter = obj => {
+      if (!obj) {
+        return;
+      }
+      let protectedFields = classLevelPermissions?.protectedFields || [];
+      if (!client.hasMasterKey && !Array.isArray(protectedFields)) {
+        protectedFields = getDatabaseController(this.config).addProtectedFields(
+          classLevelPermissions,
+          res.object.className,
+          query,
+          aclGroup,
+          clientAuth
+        );
+      }
+      return DatabaseController.filterSensitiveData(
+        client.hasMasterKey,
+        aclGroup,
+        clientAuth,
+        op,
+        classLevelPermissions,
+        res.object.className,
+        protectedFields,
+        obj,
+        query
+      );
+    };
+    res.object = filter(res.object);
+    res.original = filter(res.original);
+  }
+
   _getCLPOperation(query: any) {
     return typeof query === 'object' &&
       Object.keys(query).length == 1 &&