Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.4 and 9.4.1-alpha.3, Parse Server's readOnlyMasterKey option allows access with master-level read privileges but is documented to deny all write operations. However, some endpoints incorrectly accept the readOnlyMasterKey for mutating operations. This allows a caller who only holds the readOnlyMasterKey to create, modify, and delete Cloud Hooks and to start Cloud Jobs, wh