Since 2.2 we run all scripts with minimal privileges, similar to applets in your browser.
The problem is, they have unrestricted access to other things they can muck with (ES, JDK, whatever).
So they can still easily do tons of bad things
This PR restricts what classes scripts can load via the classloader mechanism, to make life more difficult.
The "standard" list was populated from the old list used for the groovy sandbox: though
a few more were needed for tests to pass (java.lang.String, java.util.Iterator, nothing scary there).
Additionally, each scripting engine typically needs permissions to some runtime stuff.
That is the downside of this "good old classloader" approach, but I like the transparency and simplicity,
and I don't want to waste my time with any feature provided by the engine itself for this, I don't trust them.
This is not perfect and the engines are not perfect but you gotta start somewhere. For expert users that
need to tweak the permissions, we already support that via the standard java security configuration files, the
specification is simple, supports wildcards, etc (though we do not use them ourselves).
Robert Muir
Ryan Ernst