The system must use initial TCP sequence numbers most resistant to sequence number guessing attacks.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
GEN003580-ESXI5-PF	GEN003580-ESXI5-PF	GEN003580-ESXI5-PF_rule		Medium

Description
One use of initial TCP sequence numbers is to verify bidirectional communication between two hosts, which provides some protection against spoofed source addresses being used by the connection originator. If the initial TCP sequence numbers for a host can be determined by an attacker, it may be possible to establish a TCP connection from a spoofed source address without bidirectional communication. Permanent finding - ESXi is not a general purpose OS. Network stack hardening is not configurable down to this level.

Description

One use of initial TCP sequence numbers is to verify bidirectional communication between two hosts, which provides some protection against spoofed source addresses being used by the connection originator. If the initial TCP sequence numbers for a host can be determined by an attacker, it may be possible to establish a TCP connection from a spoofed source address without bidirectional communication. Permanent finding - ESXi is not a general purpose OS. Network stack hardening is not configurable down to this level.

STIG	Date
VMware ESXi v5 Security Technical Implementation Guide	2013-01-15

Details

Check Text ( C-GEN003580-ESXI5-PF_chk )
ESXi does not support this requirement. This is a permanent finding.

Fix Text (F-GEN003580-ESXI5-PF_fix)
This requirement is a permanent finding and cannot be fixed. An appropriate mitigation for the system must be implemented but this finding cannot be considered fixed.