cis-apache24-6-1

name	cis-apache24-6.1
description	Ensure the Error Log Filename and Severity Level Are Configured Correctly
category	cis-apache
version	2.3.0
author	cyberstrike-official
tags	["cis","apache","linux","logging","monitoring","maintenance"]
cis_id	6.1
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 Error Log Filename and Severity Level Are Configured Correctly (Automated)

Profile Applicability

Level 1

Description

The LogLevel directive is used to configure the severity level for the error logs. While the ErrorLog directive configures the file name. The log level values are the standard syslog levels of emerg, alert, crit, error, warn, notice, info and debug. The recommended level is notice for most modules, so that all errors from the emerg level through notice level will be logged. The recommended setting for the core module is info so that any not found requests will be included in the error logs.

Rationale

The server error logs are invaluable because they can also be used to spot any potential problems before they occur. Most importantly, they can be used to watch for anomalous behavior such as a lot of not found or unauthorized errors may be an indication that an attack is pending or has occurred. Starting with Apache 2.4 the error log does not include the not found errors except at the info logging level. Therefore, it is important that the log level be set to info for the core module. The not found requests need to be included in the error log for both forensics' investigation and host intrusion detection purposes. Monitoring the access logs may not be practical for many web servers with high volume traffic.

Audit Procedure

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

1. Verify the LogLevel in the Apache server configuration has a value of info or lower for the core module and notice or lower for other modules. Note that it is also compliant to have a value of info or debug if there is a need for a more verbose log and the storage and monitoring processes are capable of handling the extra load. The recommended value is notice core:info.

2. Verify the ErrorLog directive is configured to an appropriate log file or syslog facility.