fix: Denial of service via unindexed database query for unconfigured auth providers ([GHSA-g4cf-xj29-wqqr](https://github.com/parse-community/parse-server/security/advisories/GHSA-g4cf-xj29-wqqr)) (#10271)

spec/vulnerabilities.spec.js

@@ -3716,3 +3716,67 @@ describe('(GHSA-6qh5-m6g3-xhq6) LiveQuery query depth DoS via deeply nested subs
     expect(subscription).toBeDefined();
   });
 });
+
+describe('(GHSA-g4cf-xj29-wqqr) DoS via unindexed database query for unconfigured auth providers', () => {
+  it('should not query database for unconfigured auth provider on signup', async () => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+    const spy = spyOn(databaseAdapter, 'find').and.callThrough();
+    await expectAsync(
+      new Parse.User().save({ authData: { nonExistentProvider: { id: 'test123' } } })
+    ).toBeRejectedWith(
+      new Parse.Error(Parse.Error.UNSUPPORTED_SERVICE, 'This authentication method is unsupported.')
+    );
+    const authDataQueries = spy.calls.all().filter(call => {
+      const query = call.args[2];
+      return query?.$or?.some(q => q['authData.nonExistentProvider.id']);
+    });
+    expect(authDataQueries.length).toBe(0);
+  });
+
+  it('should not query database for unconfigured auth provider on challenge', async () => {
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+    const spy = spyOn(databaseAdapter, 'find').and.callThrough();
+    await expectAsync(
+      request({
+        method: 'POST',
+        url: Parse.serverURL + '/challenge',
+        headers: {
+          'X-Parse-Application-Id': Parse.applicationId,
+          'X-Parse-REST-API-Key': 'rest',
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({
+          authData: { nonExistentProvider: { id: 'test123' } },
+          challengeData: { nonExistentProvider: { token: 'abc' } },
+        }),
+      })
+    ).toBeRejected();
+    const authDataQueries = spy.calls.all().filter(call => {
+      const query = call.args[2];
+      return query?.$or?.some(q => q['authData.nonExistentProvider.id']);
+    });
+    expect(authDataQueries.length).toBe(0);
+  });
+
+  it('should still query database for configured auth provider', async () => {
+    await reconfigureServer({
+      auth: {
+        myConfiguredProvider: {
+          module: {
+            validateAppId: () => Promise.resolve(),
+            validateAuthData: () => Promise.resolve(),
+          },
+        },
+      },
+    });
+    const databaseAdapter = Config.get(Parse.applicationId).database.adapter;
+    const spy = spyOn(databaseAdapter, 'find').and.callThrough();
+    const user = new Parse.User();
+    await user.save({ authData: { myConfiguredProvider: { id: 'validId', token: 'validToken' } } });
+    const authDataQueries = spy.calls.all().filter(call => {
+      const query = call.args[2];
+      return query?.$or?.some(q => q['authData.myConfiguredProvider.id']);
+    });
+    expect(authDataQueries.length).toBeGreaterThan(0);
+  });
+});

src/Auth.js

@@ -424,7 +424,13 @@ const findUsersWithAuthData = async (config, authData, beforeFind) => {
     providers.map(async provider => {
       const providerAuthData = authData[provider];
 
-      const adapter = config.authDataManager.getValidatorForProvider(provider)?.adapter;
+      const validatorConfig = config.authDataManager.getValidatorForProvider(provider);
+      // Skip database query for unconfigured providers to avoid unindexed collection scans;
+      // the provider will be rejected later in handleAuthDataValidation with UNSUPPORTED_SERVICE
+      if (!validatorConfig?.validator) {
+        return null;
+      }
+      const adapter = validatorConfig.adapter;
       if (beforeFind && typeof adapter?.beforeFind === 'function') {
         await adapter.beforeFind(providerAuthData);
       }