[CentOS] an actual hacked machine, in a preserved state

> 1.) Attacker uses apache remote exploit (or other means) to obtain

>  your /etc/shadow file (not a remote shell, just GET the file 
> without that fact being logged);

I don't mean to thread-hijack, but I'm curious, if apache runs as its
own non-root user and /etc/shadow is root-owned and 0400, then
how could any exploit of software not running as root ever have
access to that file??