Details

Information flow control regulates where information is allowed to travel within a network and between interconnected networks. Blocking or restricting detected harmful or suspicious communications between interconnected networks enforces approved authorizations for controlling the flow of traffic.

The firewall that filters traffic outbound to interconnected networks with different security policies must be configured to permit or block traffic based on organization-defined traffic authorizations.

Solution

Step 1: Configure the ingress ACL similar to the example below.

ASA(config)# access-list INSIDE_INextended permit tcp any any eq https
ASA(config)# access-list INSIDE_INextended permit tcp any any eq http
ASA(config)# access-list INSIDE_INextended permit tcp any any eq …
ASA(config)# access-list INSIDE_INextended deny ip any any log

Step 2: Apply the ACL inbound on all internal interfaces as shown in the example below.

ASA(config)# access-group INSIDE_IN in interface INSIDE
ASA(config)# end

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_ASA_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Access Control.This control applies to the following type of system Cisco.

References

• 800-53|AC-4
• CAT|I
• CCI|CCI-001414
• Rule-ID|SV-239852r665842_rule
• STIG-ID|CASA-FW-000010
• Vuln-ID|V-239852

Source

• Tenable.com/audits