cis-apache24-10-2

name	cis-apache24-10.2
description	Ensure the LimitRequestFields Directive is Set to 100 or Less but not 0 (Automated)
category	cis-apache
version	2.3.0
author	cyberstrike-official
tags	["cis","apache","linux","request-limits","buffer-overflow","limit-request-fields"]
cis_id	10.2
cis_benchmark	CIS Apache HTTP Server 2.4 Benchmark v2.3.0
tech_stack	["linux","apache"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

Ensure the LimitRequestFields Directive is Set to 100 or Less but not 0 (Automated)

Profile Applicability

• Level 2

Description

The LimitRequestFields directive limits the number of fields allowed in an HTTP request.

Rationale

The limiting of the number of fields is helpful so that the web server can prevent an unexpectedly high number of fields from being passed to a potentially vulnerable CGI program, module or application that would have attempted to process the request. Of course, the underlying dependency is that we need to set the limits high enough to not interfere with any one application on the server, while setting them low enough to be of value in protecting the applications. Since the configuration directives are available only at the server configuration level, it is not possible to tune the value for different portions of the same web server. Please read the Apache documentation carefully, as these requests may interfere with the expected functionality of some web applications.

Audit

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

Verify that the LimitRequestFields directive is in the Apache configuration and has a value of 100 or less but not 0.

Remediation

Perform the following to implement the recommended state:

Add or modify the LimitRequestFields directive in the Apache configuration to have a value of 100 or less but not 0. If the directive is not present the default depends on a compile time configuration, but defaults to a value of 100.

LimitRequestFields 100

Default Value

LimitRequestFields 100

References

1. https://httpd.apache.org/docs/2.4/mod/core.html#limitrequestfields

CIS Controls

v8:

• 4.2 Establish and Maintain a Secure Configuration Process for Network Infrastructure
  • Establish and maintain a secure configuration process for network devices. Review and update documentation annually, or when significant enterprise changes occur that could impact this Safeguard.

v7:

• 5.1 Establish Secure Configurations
  • Maintain documented, standard security configuration standards for all authorized operating systems and software.