LAMP Web Application Ownership and Permissions

November 29, 2015 1.1k views
Security PHP PHP Frameworks Linux Basics LAMP Stack LEMP

I've read a lot of articles on the subject of setting ownership and permissions for web servers and found good information, but I still can't settle on the right answer. Are you able to help?

The scenario:

A small number of low profile websites, all of which need write access for logs, cache, etc. Updates are deployed frequently by using git over SSH. All are sites I have coded and am managing, so it's only me that accesses the box. The server doesn't do anything else other than LAMP.

The default position seems to be:

  • Apache/mod_php runs as www-data user
  • File ownership set to root:www-data
  • Permissions set to 755 except for the logs/cache/etc which will be 775.

I could do this by running a deploy script as root that updates the site and resets all the ownership and permissions. I would have to use a long/complex password for every change and adding a file will need chown/chmod.

This is OK, but this seems to be a much more convenient configuration:

  • Create user account web, set Apache/mod_php to run as this user.
  • Store all websites as subfolders of /home/web.
  • Can deploy, edit and update all as user web via SSH without further authentication.
  • Use sudo with strong password for system configuration

The benefits of the former method would be that write permissions are more limited, but if you can write at all then how much does that matter? It might be harder to escalate permissions as www-data than as a user with sudo access, but is brute forcing a strong password a realistic attack?

Can anyone offer advice or an alternative?


1 Answer

Brute force attacks should be a concern but you could easily set the web user to only be accessible via ssh with a key and set up your SFTP client to use the key instead of a password.

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