5.5. Securing Apache HTTP Server
The Apache HTTP Server is one of the most stable and secure services that ships
with Red Hat Linux. There are an overwhelming number of options and techniques
available to secure the Apache HTTP Server — too numerous to delve into
deeply here.
It is important if you are configuring Apache HTTP Server to read the documentation
available for the application. This includes the the chapter titled
Apache HTTP Server in the Red Hat Linux Reference Guide,
the chapter titled Apache HTTP Secure Server
Configuration in the Red Hat Linux Customization Guide, and
the Stronghold manuals, available at http://www.redhat.com/docs/manuals/stronghold/.
Below is a list of configuration options administrators should be
careful using.
5.5.1. FollowSymLinks
This directive is enabled by default, so be careful where you create
symbolic links to in the document root of the Web server. For instance, it
is a bad idea to provide a symbolic link to /.
5.5.2. The Indexes Directive
This directive is enabled by default, but may not be desirable. If you
do not want users to browse files on the server, it is best to remove
this directive.
5.5.3. The UserDir Directive
The UserDir directive is disabled by
default because it can confirm the presence of a user account on the
system. If you wish to enable user directory browsing on the server,
use the following directives:
UserDir enabled
UserDir disabled root |
These directives activate user directory browsing for all user
directories other than /root. If you wish to add
users to the list of disabled accounts, add a space delimited list of
users on the UserDir disabled line.
5.5.4. Do Not Remove the IncludesNoExec
Directive
By default, the server-side includes module cannot execute
commands. It is ill advised to change this setting unless you
absolutely have to, as it could potentially enable an attacker to
execute commands on the system.
5.5.5. Restrict Permissions for Executable Directories
Be certain to only assign write permissions only to the root user for
any directory containing scripts or CGIs. This can be accomplished by
typing the following commands:
chown root <directory_name>
chmod 755 <directory_name> |
Also, always verify that any scripts you are running work as intended
before putting them into production.
