The system is configured to allow SYN attacks.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-4117	3.102	SV-29611r1_rule	ECSC-1	Low

Description
Adjusts retransmission of TCP SYN-ACKs. When enabled, connection responses time out more quickly in the event of a SYN DoS attack.

STIG	Date
Windows 2003 Domain Controller Security Technical Implementation Guide	2015-06-03

Details

Check Text ( C-314r1_chk )
Analyze the system using the Security Configuration and Analysis snap-in. Expand the Security Configuration and Analysis tree view. Navigate to Local Policies -> Security Options. If the value for “MSS: (SynAttackProtect) Syn attack protection level (protects against DoS)” is not set to “Connections time out sooner if a SYN attack is detected”, then this is a finding. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \System\CurrentControlSet\Services\Tcpip\Parameters\ Value Name: SynAttackProtect Value Type: REG_DWORD Value: 1

Check Text ( C-314r1_chk )

Analyze the system using the Security Configuration and Analysis snap-in.
Expand the Security Configuration and Analysis tree view.
Navigate to Local Policies -> Security Options.

If the value for “MSS: (SynAttackProtect) Syn attack protection level (protects against DoS)” is not set to “Connections time out sooner if a SYN attack is detected”, then this is a finding.

The policy referenced configures the following registry value:

Registry Hive: HKEY_LOCAL_MACHINE
Registry Path: \System\CurrentControlSet\Services\Tcpip\Parameters\

Value Name: SynAttackProtect

Value Type: REG_DWORD
Value: 1

Fix Text (F-5725r1_fix)
Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> “MSS: (SynAttackProtect) Syn attack protection level (protects against DoS)” to “Connections time out sooner if a SYN attack is detected”.