Details

The firewall must reject requests for access or services where the source address received by the firewall specifies a loopback address.

The loopback address is used by an Inter-Processor Control (IPC) mechanism that enables the client and server portion of an application running on the same machine to communicate, and so it is trusted. It should never be used as the source IP address of an inbound or outbound transmission.

Solution

Establish filters to block any attempt from the firewall or any network to pass any packets claiming to be from a loopback address.

Supportive Information

The following resource is also helpful.

• https://iasecontent.disa.mil/stigs/zip/U_Network_Firewall_V8R25_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Cisco.

References

• 800-53|SC-7(5)
• 800-53|SC-7(15)
• CAT|II
• Rule-ID|SV-15270r2_rule
• STIG-ID|NET0380
• Vuln-ID|V-14644

Source

• Tenable.com/audits