The system must be configured to limit how often keep-alive packets are sent.

From Windows 8/8.1 Security Technical Implementation Guide

Associated with: CCI-002385

SV-48125r1_rule The system must be configured to limit how often keep-alive packets are sent.

Vulnerability discussion

This setting controls how often TCP sends a keep-alive packet in attempting to verify that an idle connection is still intact. A higher value could allow an attacker to cause a denial of service with numerous connections.

Check content

Analyze the system using the Security Configuration and Analysis snap-in. (See "Performing Analysis with the Security Configuration and Analysis Snap-in" in the STIG Overview document.) Expand the Security Configuration and Analysis tree view. Navigate to Local Policies -> Security Options. (See "Updating the Windows Security Options File" in the STIG Overview document if MSS settings are not visible in the system's policy tools.) If the value for "MSS: (KeepAliveTime) How often keep-alive packets are sent in milliseconds" is not set to "300000 or 5 minutes (recommended)" or less, this is a finding. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Subkey: \System\CurrentControlSet\Services\Tcpip\Parameters\ Value Name: KeepAliveTime Value Type: REG_DWORD Value: 300000

Fix text

Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> "MSS: (KeepAliveTime) How often keep-alive packets are sent in milliseconds" to "300000 or 5 minutes (recommended)" or less.

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