By using the `resource_type` service, an attacker could cause puppet to load arbitrary Ruby files from the puppet master node’s file system. While this behavior is not enabled by default, `auth.conf` settings could be modified to allow it. The exploit requires local file system access to the Puppet Master.
Puppet Module Tool (PMT) did not correctly control permissions of modules it installed, instead transferring permissions that existed when the module was built.
You must update puppet.