Adobe’s Flash Plugin is well known for its security flaws and for causing browser crashes. ManageIQ got rid of Flash already in the Anand Release and replaced all relevant parts of the code with a JavaScript library to render graphs and diagrams. Finally Red Hat CloudForms 4.2 was released and is now using the same JavaScript library and does not require Flash anymore.
So the first thing I did is running the following command on all my machines:
1rpm -e flash-plugin