zopefoundation's Products.CMFCore vulnerable to unauthenticated denial of service and crash via unchecked use of input with Python's marshal module

Products.CMFCore are the key framework services for the Zope Content Management Framework (CMF). The use of Python's marshal module to handle unchecked input in a public method on `PortalFolder` objects can lead to an unauthenticated denial of service and crash situation. The code in question is exposed by all portal software built on top of `Products.CMFCore`, such as Plone. All deployments are vulnerable. The code has been fixed in `Products.CMFCore` version 3.2.