I am running some Wordpress blogs for friends/family on a linux box and I would like to prevent the compromise of one from being able to inflict damage to all. It hasn't happened yet, but one of the bloggers installs every add-in and theme she can find, one of them will inevitably contain a vulnerability--it's just a matter of time.
I am using the stock Amazon Linux Apache/PHP install so I basically have a bunch of preforked apache processes all running as the same user and the application directories are all owned by www-data. What I would prefer is for all installations to run as different users, but I would like to avoid having to dork with FastCGI. Is it possible to be isolate in that manner when using mod_php?
Edit: If there is a solution to that problem that doesn't involve separate uses for each directory, I am also fine with that. Any technique that works will be appreciated.