TCP connection response retransmissions are not controlled.

From Windows 2003 Domain Controller Security Technical Implementation Guide

Part of TCP Connection Response Retransmissions

Associated with IA controls: ECSC-1

SV-29612r1_rule TCP connection response retransmissions are not controlled.

Vulnerability discussion

In a SYN flood attack, the attacker sends a continuous stream of SYN packets to a server, and the server leaves the half-open connections open until it is overwhelmed and no longer is able to respond to legitimate requests.

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Fix text

Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> “MSS: (TcpMaxConnectResponseRetransmissions) SYN-ACK retransmissions when a connection is not acknowledged” to “3 & 6 seconds, half-open connections dropped after 21 seconds”, “3 seconds, half-open connections dropped after 9 seconds” or “No retransmission, half-open connections dropped after 3 seconds”.

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