The IDPS must check inbound traffic to ensure the communications are coming from an authorized source and routed to an authorized destination.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-34710	SRG-NET-000195-IDPS-00143	SV-45597r1_rule		Medium

Description
Spoofing source addresses occurs when a malicious user outside the network has created packets with a source address belonging to the private address space of the target network. This is done in an attempt to slip through the perimeter as a member host to gain access to internal resources or to conceal identity to perform an attack. It is imperative that all inbound and outbound traffic with spoofed or invalid source addresses are blocked. If inbound traffic is not monitored to make sure source and destination of packets are authorized, then malicious users outside the network may be able to send packets to the private, trusted network. Typically, this function is performed by the network firewall. However, some newer IDPS products are able to perform this function.

Description

Spoofing source addresses occurs when a malicious user outside the network has created packets with a source address belonging to the private address space of the target network. This is done in an attempt to slip through the perimeter as a member host to gain access to internal resources or to conceal identity to perform an attack. It is imperative that all inbound and outbound traffic with spoofed or invalid source addresses are blocked. If inbound traffic is not monitored to make sure source and destination of packets are authorized, then malicious users outside the network may be able to send packets to the private, trusted network. Typically, this function is performed by the network firewall. However, some newer IDPS products are able to perform this function.

STIG	Date
Intrusion Detection and Prevention Systems (IDPS) Security Requirements Guide	2012-11-19

Details

Check Text ( C-42957r1_chk )
If this function is performed by another network element, this is not a finding. Verify sensor rules exist that monitor inbound traffic to ensure the communications are coming from an authorized source and routed to an authorized destination. If rules do not exist to monitor inbound traffic to ensure the communications are coming from an authorized source and routed to an authorized destination, this is a finding.

Check Text ( C-42957r1_chk )

If this function is performed by another network element, this is not a finding.

Verify sensor rules exist that monitor inbound traffic to ensure the communications are coming from an authorized source and routed to an authorized destination.

If rules do not exist to monitor inbound traffic to ensure the communications are coming from an authorized source and routed to an authorized destination, this is a finding.

Fix Text (F-38995r1_fix)
Implement sensor rules to monitor inbound traffic to ensure the communications are coming from an authorized source and routed to an authorized destination.