eZ Publish 4.2 installation in eZDFSFileHandler cluster environment, allows viewing hidden articles in front end

Steps to reproduce

• Publish an article
• Open the article in the front end on any node (keep that browser tab opened for later)
• Access the article in the back end and toggle it's visibility to hidden
• Reselect the browser tab with the article in front end
• Refresh the window. It will show an error indicating "Access denied"
• Refresh again, it will show a kernel error but, it will also show an unformatted version of the article