fix: GraphQL error messages disclose required input field names when public introspection is disabled (GHSA-2fgh-8j2g-w354)

spec/ParseGraphQLServer.spec.js

@@ -1231,6 +1231,132 @@ describe('ParseGraphQLServer', () => {
             expect(error.message).toContain('secretAdminTask');
           }
         });
+
+        it('should strip required-field names from base coercion errors without master or maintenance key', async () => {
+          const schemaController = await parseServer.config.databaseController.loadSchema();
+          await schemaController.addClassIfNotExists('TestReqClass', {
+            secretRequiredField: { type: 'String', required: true },
+          });
+          await resetGraphQLCache();
+
+          try {
+            await apolloClient.mutate({
+              mutation: gql`
+                mutation Create($input: CreateTestReqClassInput!) {
+                  createTestReqClass(input: $input) {
+                    testReqClass {
+                      id
+                    }
+                  }
+                }
+              `,
+              variables: { input: { fields: {} } },
+            });
+            fail('should have thrown a coercion error');
+          } catch (e) {
+            const error = getReturnedError(e);
+            // The base graphql-js "... was not provided." coercion message carries no
+            // "Did you mean" clause, so it discloses the required custom field name to a
+            // caller who only has the public application id. It must be redacted.
+            expect(error.message).not.toContain('secretRequiredField');
+            // The message is duplicated into extensions.stacktrace in non-production;
+            // ensure the identifier does not leak through any returned field.
+            expect(JSON.stringify(error)).not.toContain('secretRequiredField');
+          }
+        });
+
+        it('should keep required-field names in base coercion errors with master key', async () => {
+          const schemaController = await parseServer.config.databaseController.loadSchema();
+          await schemaController.addClassIfNotExists('TestReqClass', {
+            secretRequiredField: { type: 'String', required: true },
+          });
+          await resetGraphQLCache();
+
+          try {
+            await apolloClient.mutate({
+              mutation: gql`
+                mutation Create($input: CreateTestReqClassInput!) {
+                  createTestReqClass(input: $input) {
+                    testReqClass {
+                      id
+                    }
+                  }
+                }
+              `,
+              variables: { input: { fields: {} } },
+              context: {
+                headers: {
+                  'X-Parse-Master-Key': 'test',
+                },
+              },
+            });
+            fail('should have thrown a coercion error');
+          } catch (e) {
+            const error = getReturnedError(e);
+            expect(error.message).toContain('secretRequiredField');
+          }
+        });
+
+        it('should keep required-field names in base coercion errors when public introspection is enabled', async () => {
+          const parseServer = await reconfigureServer();
+          await createGQLFromParseServer(parseServer, { graphQLPublicIntrospection: true });
+          const schemaController = await parseServer.config.databaseController.loadSchema();
+          await schemaController.addClassIfNotExists('TestReqClass', {
+            secretRequiredField: { type: 'String', required: true },
+          });
+          await resetGraphQLCache();
+
+          try {
+            await apolloClient.mutate({
+              mutation: gql`
+                mutation Create($input: CreateTestReqClassInput!) {
+                  createTestReqClass(input: $input) {
+                    testReqClass {
+                      id
+                    }
+                  }
+                }
+              `,
+              variables: { input: { fields: {} } },
+            });
+            fail('should have thrown a coercion error');
+          } catch (e) {
+            const error = getReturnedError(e);
+            expect(error.message).toContain('secretRequiredField');
+          }
+        });
+
+        it('should strip required-field names from inline-literal coercion errors without master or maintenance key', async () => {
+          const schemaController = await parseServer.config.databaseController.loadSchema();
+          await schemaController.addClassIfNotExists('TestReqClass', {
+            secretRequiredField: { type: 'String', required: true },
+          });
+          await resetGraphQLCache();
+
+          try {
+            // Input written inline in the operation (not via a variable) is validated by
+            // ValuesOfCorrectTypeRule, which emits a type-qualified message
+            // ('Field "<Type>.<field>" of required type ...'), disclosing both the generated
+            // input type name (which embeds the class name) and the required field name.
+            await apolloClient.mutate({
+              mutation: gql`
+                mutation Create {
+                  createTestReqClass(input: { fields: {} }) {
+                    testReqClass {
+                      id
+                    }
+                  }
+                }
+              `,
+            });
+            fail('should have thrown a validation error');
+          } catch (e) {
+            const error = getReturnedError(e);
+            expect(error.message).not.toContain('secretRequiredField');
+            expect(error.message).not.toContain('CreateTestReqClass');
+            expect(JSON.stringify(error)).not.toContain('secretRequiredField');
+          }
+        });
       });
 
 

src/GraphQL/ParseGraphQLServer.js

@@ -104,6 +104,27 @@ const IntrospectionControlPlugin = (publicIntrospection) => ({
 const stripSchemaSuggestion = message =>
   typeof message === 'string' ? message.replace(/ ?Did you mean(.+?)\?$/, '') : message;
 
+// graphql-js also emits a base input-coercion message that names a schema
+// identifier WITHOUT a "Did you mean" clause, so the suggestion strip above
+// cannot reach it: when a required custom input field is omitted, coerceInputValue
+// returns 'Field "<name>" of required type "<type>" was not provided.', disclosing
+// a field name the caller never supplied. Redact the quoted identifiers from this
+// template while preserving the error shape, for callers that are not allowed to
+// introspect. The sibling coercion messages ('... is not defined by type "<type>".',
+// 'Expected type "<type>" to be an object.') are intentionally left intact: they
+// only echo an input type name the caller already referenced in the operation, so
+// they disclose nothing the caller did not already provide.
+const stripSchemaCoercionIdentifiers = message =>
+  typeof message === 'string'
+    ? message.replace(
+      /Field "[^"]*" of required type "[^"]*" was not provided\./g,
+      'Field of required type was not provided.'
+    )
+    : message;
+
+const stripSchemaIdentifiers = message =>
+  stripSchemaCoercionIdentifiers(stripSchemaSuggestion(message));
+
 const SchemaSuggestionsControlPlugin = (publicIntrospection) => ({
   requestDidStart: async (requestContext) => ({
     willSendResponse: async () => {
@@ -124,9 +145,9 @@ const SchemaSuggestionsControlPlugin = (publicIntrospection) => ({
             ? body.initialResult.errors
             : undefined;
       errors?.forEach(error => {
-        error.message = stripSchemaSuggestion(error.message);
+        error.message = stripSchemaIdentifiers(error.message);
         if (Array.isArray(error.extensions?.stacktrace)) {
-          error.extensions.stacktrace = error.extensions.stacktrace.map(stripSchemaSuggestion);
+          error.extensions.stacktrace = error.extensions.stacktrace.map(stripSchemaIdentifiers);
         }
       });
     },