Cis Apache24 4.3

4.3 Ensure OverRide Is Disabled for the OS Root Directory

Profile Applicability

• Level 1

Description

The Apache AllowOverride directive and the new AllowOverrideList directive allow for .htaccess files to be used to override much of the configuration, including authentication, handling of document types, auto generated indexes, access control, and options. When the server finds an .htaccess file (as specified by AccessFileName) it needs to know which directives declared in that file can override earlier access information. When this directive is set to None, then .htaccess files are completely ignored. In this case, the server will not even attempt to read .htaccess files in the filesystem. When this directive is set to All, then any directive which has the .htaccess Context is allowed in the .htaccess files.

Rationale

While the functionality of htaccess files is sometimes convenient, usage decentralizes the access controls and increases the risk of configurations being changed or viewed inappropriately by an unintended rogue .htaccess file. Consider also that some of the more common vulnerabilities in web servers and web applications allow the web files to be viewed or to be modified, then it is wise to keep the configuration out of the web server from being placed in .htaccess files.

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 element.
2. Ensure there is a single AllowOverride directive with the value of None.
3. Ensure there are no AllowOverrideList directives present.

The following may be useful for extracting root directory elements from the Apache configuration for auditing.

$ perl -ne 'print if /^ *<Directory *\/\/i .. /<\/Directory>/i'
$APACHE_PREFIX/conf/httpd.conf

Remediation

Perform the following to implement the recommended state:

1. Search the Apache configuration files (httpd.conf and any included configuration files) to find a root <Directory> element.
2. Remove any AllowOverrideList directives found.
3. Add a single AllowOverride directive if there is none.
4. Set the value for AllowOverride to None.

<Directory />
   . . .
   AllowOverride None
   . . .
</Directory>

Default Value

The following is the default root directory configuration:

<Directory />
   . . .
   AllowOverride None
   . . .
</Directory>

References

1. https://httpd.apache.org/docs/2.4/mod/core.html#allowoverride
2. https://httpd.apache.org/docs/2.4/mod/core.html#allowoverridelist

CIS Controls

Controls Version: v8

• 3.3 Configure Data Access Control Lists
  • Configure data access control lists based on a user's need to know. Apply data access control lists, also known as access permissions, to local and remote file systems, databases, and applications.
  • IG 1: •
  • IG 2: •
  • IG 3: •

Controls Version: v7

• 14.6 Protect Information through Access Control Lists
  • Protect all information stored on systems with file system, network share, claims, application, or database specific access control lists. These controls will enforce the principle that only authorized individuals should have access to the information based on their need to access the information as a part of their responsibilities.
  • IG 1: •
  • IG 2: •
  • IG 3: •

Profile

• Level 1 | Automated