fix: GraphQL "Did you mean" validation suggestions disclose schema to unauthenticated callers ([GHSA-8cph-rgr4-g5vj](GHSA-8cph-rgr4-g5vj)) (#10468)

Author: mtrezza

spec/ParseGraphQLServer.spec.js

@@ -715,6 +715,115 @@ describe('ParseGraphQLServer', () => {
             })
           expect(introspection.data).toBeDefined();
         });
+
+        it('should strip "Did you mean" field suggestions from validation errors without master or maintenance key', async () => {
+          try {
+            await apolloClient.query({
+              query: gql`
+                query Typo {
+                  healt
+                }
+              `,
+            });
+            fail('should have thrown a validation error');
+          } catch (e) {
+            const message = e.networkError.result.errors[0].message;
+            expect(message).toContain('Cannot query field "healt"');
+            expect(message).not.toMatch(/Did you mean/);
+            expect(message).not.toContain('health');
+          }
+        });
+
+        it('should strip "Did you mean" argument suggestions from validation errors without master or maintenance key', async () => {
+          try {
+            await apolloClient.query({
+              query: gql`
+                query UnknownArg {
+                  users(wher: {}) {
+                    edges {
+                      node {
+                        id
+                      }
+                    }
+                  }
+                }
+              `,
+            });
+            fail('should have thrown a validation error');
+          } catch (e) {
+            const message = e.networkError.result.errors[0].message;
+            expect(message).toContain('Unknown argument "wher"');
+            expect(message).not.toMatch(/Did you mean/);
+            expect(message).not.toContain('"where"');
+          }
+        });
+
+        it('should keep "Did you mean" suggestions with master key', async () => {
+          try {
+            await apolloClient.query({
+              query: gql`
+                query Typo {
+                  healt
+                }
+              `,
+              context: {
+                headers: {
+                  'X-Parse-Master-Key': 'test',
+                },
+              },
+            });
+            fail('should have thrown a validation error');
+          } catch (e) {
+            const message = e.networkError.result.errors[0].message;
+            expect(message).toContain('Cannot query field "healt"');
+            expect(message).toMatch(/Did you mean/);
+            expect(message).toContain('health');
+          }
+        });
+
+        it('should keep "Did you mean" suggestions with maintenance key', async () => {
+          try {
+            await apolloClient.query({
+              query: gql`
+                query Typo {
+                  healt
+                }
+              `,
+              context: {
+                headers: {
+                  'X-Parse-Maintenance-Key': 'test2',
+                },
+              },
+            });
+            fail('should have thrown a validation error');
+          } catch (e) {
+            const message = e.networkError.result.errors[0].message;
+            expect(message).toContain('Cannot query field "healt"');
+            expect(message).toMatch(/Did you mean/);
+            expect(message).toContain('health');
+          }
+        });
+
+        it('should keep "Did you mean" suggestions when public introspection is enabled', async () => {
+          const parseServer = await reconfigureServer();
+          await createGQLFromParseServer(parseServer, { graphQLPublicIntrospection: true });
+
+          try {
+            await apolloClient.query({
+              query: gql`
+                query Typo {
+                  healt
+                }
+              `,
+            });
+            fail('should have thrown a validation error');
+          } catch (e) {
+            const message = e.networkError.result.errors[0].message;
+            expect(message).toContain('Cannot query field "healt"');
+            expect(message).toMatch(/Did you mean/);
+            expect(message).toContain('health');
+          }
+        });
       });
 
 

src/GraphQL/ParseGraphQLServer.js

@@ -50,6 +50,33 @@ const IntrospectionControlPlugin = (publicIntrospection) => ({
 
 });
 
+// graphql-js validation rules (FieldsOnCorrectTypeRule, KnownArgumentNamesRule,
+// KnownTypeNamesRule, ...) embed "Did you mean ...?" hints sourced from the live
+// schema in their error messages. Those messages are returned to the caller
+// before didResolveOperation runs, so they sidestep IntrospectionControlPlugin
+// and disclose schema identifiers the introspection guard is meant to hide.
+// Strip the hint suffix for callers that are not allowed to introspect.
+const SchemaSuggestionsControlPlugin = (publicIntrospection) => ({
+  requestDidStart: async (requestContext) => ({
+    validationDidStart: async () => {
+      if (publicIntrospection) {
+        return;
+      }
+      const isMasterOrMaintenance =
+        requestContext.contextValue.auth?.isMaster ||
+        requestContext.contextValue.auth?.isMaintenance;
+      if (isMasterOrMaintenance) {
+        return;
+      }
+      return async (validationErrors) => {
+        validationErrors?.forEach(error => {
+          error.message = error.message.replace(/ ?Did you mean(.+?)\?$/, '');
+        });
+      };
+    },
+  }),
+});
+
 class ParseGraphQLServer {
   parseGraphQLController: ParseGraphQLController;
 
@@ -111,7 +138,7 @@ class ParseGraphQLServer {
             requestHeaders: ['X-Parse-Application-Id'],
           },
           introspection: this.config.graphQLPublicIntrospection,
-          plugins: [ApolloServerPluginCacheControlDisabled(), IntrospectionControlPlugin(this.config.graphQLPublicIntrospection), createComplexityValidationPlugin(() => this.parseServer.config.requestComplexity)],
+          plugins: [ApolloServerPluginCacheControlDisabled(), IntrospectionControlPlugin(this.config.graphQLPublicIntrospection), SchemaSuggestionsControlPlugin(this.config.graphQLPublicIntrospection), createComplexityValidationPlugin(() => this.parseServer.config.requestComplexity)],
           schema,
         });
         await apollo.start();