cis-apache24-4-1

name	cis-apache24-4.1
description	Ensure Access to OS Root Directory Is Denied By Default
category	cis-apache
version	2.3.0
author	cyberstrike-official
tags	["cis","apache","linux","access-control"]
cis_id	4.1
cis_benchmark	CIS Apache HTTP Server 2.4 Benchmark v2.3.0
tech_stack	["linux","apache"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

4.1 Ensure Access to OS Root Directory Is Denied By Default

Profile Applicability

• Level 1

Description

The Apache Directory directive allows for directory specific configuration of access controls and many other features and options. One important usage is to create a default deny policy that does not allow access to operating system directories and files, except for those specifically allowed. This is done by denying access to the OS root directory.

Rationale

One aspect of Apache, which is occasionally misunderstood, is the feature of default access. That is, unless you take steps to change it, if the server can find its way to a file through normal URL mapping rules, it can and will serve it to clients. Having a default deny is a predominate security principle, and then helps prevent the unintended access, and we do that in this case by denying access to the OS root directory using either of two methods but not both:

1. Using the Apache Deny directive along with an Order directive.
2. Using the Apache Require directive.

Either method is effective. The Order/Deny/Allow combination are now deprecated; they provide three passes where all the directives are processed in the specified order. In contrast, the Require directive works on the first match similar to firewall rules. The Require directive is the default for Apache 2.4 and is demonstrated in the remediation procedure as it may be less likely to be misunderstood.

Audit

Perform the following to determine if the recommended state is implemented:

1. Search the Apache configuration files (httpd.conf and any included configuration files) to find a root <Directory> element.
2. Ensure that either one of the following two methods are configured:

Using the deprecated Order/Deny/Allow method:

1. Ensure there is a single Order directive with the value of deny, allow
2. Ensure there is a Deny directive, and with the value of from all.
3. Ensure there are no Allow or Require directives in the root <Directory> element.

Using the Require method:

4. Ensure there is a single Require directive with the value of