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V-251669

CAT III (Low)

Splunk Enterprise must be configured to send an immediate alert to the system administrator (SA) and information system security officer (ISSO) (at a minimum) when allocated log record storage volume reaches 75 percent of the repository maximum log record storage capacity.

Rule ID

SV-251669r961398_rule

STIG

Splunk Enterprise 8.x for Linux Security Technical Implementation Guide

Version

V2R3

CCIs

CCI-001855

Discussion

If security personnel are not notified immediately upon storage volume utilization reaching 75 percent, they are unable to plan for storage capacity expansion. Although this may be part of the operating system function, for the enterprise events management system, this is most often a function managed through the application since it is a critical function and requires the use of a large amount of external storage.

Check Content

Perform the following checks. If any do not comply, this is a finding.

1. Examine the file in the Splunk installation folder:

Note: If necessary, run the "btool" app within Splunk to first determine where the effective setting is contained, then validate/change that setting.

SPLUNK_HOME/etc/system/local/server.conf

Locate the following setting:

[diskUsage]
minFreeSpace = xxxx

Verify that the value is set to 25 percent of the size of the storage volume. For example, 25 percent of a 100GB drive is 25GB, and the value set would be 25000, as the value is in megabytes.

2. Examine the file in the Splunk installation folder:

$SPLUNK_HOME/etc/system/local/health.conf

Locate the following setting:

[alert_action:email]
disabled = 0
action.to =
action.cc =

Verify that the email addresses of the ISSO and SA are set to receive alerts. This email address can be a group address (example alerts@domain.com) that contain the addresses of the ISSO and SA.

3. In the Splunk console, select Settings >> Health Report Manager >> feature:disk_space.

Verify Red setting is 1, and Yellow setting is 2.

Fix Text

Perform the following fixes.

1. Edit the file in the Splunk installation folder:

$SPLUNK_HOME/etc/system/local/server.conf

Add the following lines:

[diskUsage]
minFreeSpace = xxxx

Set the value to 25 percent of the size of the storage volume. For example, 25 percent of a 100GB drive is 25GB, and the value set would be 25000, as the value is in megabytes.

2. Examine the file in the Splunk installation folder:

$SPLUNK_HOME/etc/system/local/health.conf

Add the following lines:

[alert_action:email]
disabled = 0
action.to =
action.cc =

Set the email addresses of the ISSO and SA to be able to receive alerts. This email address can be a group address (example alerts@domain.com) that contain the addresses of the ISSO and SA.

3. In the Splunk console, select Settings >> Health Report Manager >> feature:disk_space.

Set the Red setting to 1, and Yellow setting to 2.