Re: Unix Permissions: Using groups to isolate users from webserver

[Alexander Klimov <alserkli () inbox ru>]

On Mon, 29 Nov 2004, drax wrote:
> I am running a server, which has user accounts accessible through ssh and is
> running a few services, moreover, apache for serving http. Some of these users
> have vhosts, and therefor apache goes in various user's home dir to fetch the
> webpages. I need the users to have full control of their vhost'ed files, and
> that is why they are in their respective $HOME and belong to them.
Note that it does not matter where the file resides -- to be readable/writable
the only thing matters is its access mode.

> Some of their web pages (php scripts,etc) need to be able to write to the
> filesystem. Therefor apache must be able to write in those particular parts of
> their $HOME. Additionally, some of their web scripts (conf files with SQL
> passwords, etc), need to be protected from other users. But obvisouly, still
> be accessible by apache.
>
> The way I solved this problem is the following:
> [...]
> Do you believe my setup is correct and up to the task, or could it be
> circumvented in a matter of minutes?

Since your webserver is always executed with the same UID which allows to
read/write all users' data then every user who can execute something on it has
exactly the same abilities.

The proper way to solve your problem is to execute scripts with UIDs of
respected users:
  http://httpd.apache.org/docs/suexec.html

Note, that since usually php executed inside httpd you need to switch to CGI
mode or use different UIDs for httpds for different vhosts (AFAIK this is
greatly simplified by Apache 2).

-- 
Regards,
ASK