Duju is a Drupal sandbox machine

I sure hope it's possible, although don't really know enough about server security in a shared hosting environment I've identified a two key areas where security could be improved upon.

• The biggest security issue that I see at the moment is that you have to allow the web server sudo access in order to create and jail the users. This means that anybody who can execute PHP code can also do these things, which is not safe. It's a difficult problem from what I've understand, with the catch-22 being that in order to implement an automated shared/multi hosting environment, you have to allow the web server access to commands it shouldn't be allowed to use in a shared environment. One solution that I read described a process whereupon the web server creates/appends a text file on the server with the necessary arguments to add the users, etc, and then a script periodically running as the root user looks for new values in that file and reacts accordingly. Even this solution is open to holes (i.e. a shared user knows the location of this file and writes to it, being able to create new dujus), but at least they don't have direct access to the commands. I'd love to hear other possible options!
• The other major issue is that by using the method described by Alex Schenker here, one can use the web server to read the settings.php file of another web site, and hence be able to access, download, alter, and destroy data that does not belong to them. This seems to be an issue with Drupal multisite hosting in general. Please correct me if I'm wrong! Alex does describe a possible solution for this:
  1. "Only administrators of the multisites should have access to the PHP input format that would enable them to do this in the first place, and never give the owners uid = 1."
  2. "If you need PHP input for users, run each user's php process as fast-cgi and only link their sites subdirectory from the primary installation."
  3. "It's recommended that you use a Virtual Host setup to begin with. You can also set up chrooted Apache environments. A V-host will usually do this for you."

  The purpose of the Duju as it exists is to expose users to a development environment with PHP (i.e. filesystem) access, so obviously #1 is off the table. Users need PHP access. The other two suggestions sound like good options, but again I am no expert. Anybody who knows something about all of this, please do tell. :)

Anyhow, hope the module is helpful!