Detections
Analytics

18.9.26.4.2 Ensure 'System: Specify the maximum log file size (KB)' is set to 'Enabled: 32,768 or greater'

Information

This policy setting specifies the maximum size of the log file in kilobytes. The maximum log file size can be configured between 1 megabyte (1,024 kilobytes) and 4 terabytes (4,194,240 kilobytes) in kilobyte increments.

The recommended state for this setting is: Enabled: 32,768 or greater.

Rationale:

If events are not recorded it may be difficult or impossible to determine the root cause of system problems or the unauthorized activities of malicious users

Impact:

When event logs fill to capacity, they will stop recording information unless the retention method for each is set so that the computer will overwrite the oldest entries with the most recent ones. To mitigate the risk of loss of recent data, you can configure the retention method so that older events are overwritten as needed.

The consequence of this configuration is that older events will be removed from the logs. Attackers can take advantage of such a configuration, because they can generate a large number of extraneous events to overwrite any evidence of their attack. These risks can be somewhat reduced if you automate the archival and backup of event log data.

Ideally, all specifically monitored events should be sent to a server that uses Microsoft System Center Operations Manager (SCOM) or some other automated monitoring tool. Such a configuration is particularly important because an attacker who successfully compromises a server could clear the Security log. If all events are sent to a monitoring server, then you will be able to gather forensic information about the attacker's activities.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled: 32,768 or greater:

Computer Configuration\Policies\Administrative Templates\Windows Components\Event Log Service\System\Specify the maximum log file size (KB)

Note: This Group Policy path is provided by the Group Policy template EventLog.admx/adml that is included with all versions of the Microsoft Windows Administrative Templates.

Note #2: In older Microsoft Windows Administrative Templates, this setting was initially named Maximum Log Size (KB), but it was renamed starting with the Windows 8.0 & Server 2012 (non-R2) Administrative Templates.

Default Value:

Disabled. (The default log size is 20,480 KB - this value can be changed by the local administrator using the Log Properties dialog.)

See Also

https://workbench.cisecurity.org/benchmarks/14249

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-4, CCE|CCE-35288-0, CSCv7|6.4

Plugin: Windows

Control ID: 8e373400b88ac6694c63e313bd5e444a613bdc6251bea2a1859c0648cdd746fe