Title

The ALG must deny network communications traffic by default and allow network communications traffic by exception (i.e., deny all, permit by exception). (Cat II impact)

Discussion

A deny-all, permit-by-exception network communications traffic policy ensures that only those connections which are essential and approved are allowed. As a managed interface, the ALG must block all inbound and outbound network communications traffic to the application being managed and controlled unless a policy filter is installed to explicitly allow the traffic. The allow policy filters must comply with the site's security policy. A deny all, permit by exception network communications traffic policy ensures that only those connections which are essential and approved, are allowed. This requirement applies to both inbound and outbound network communications traffic. All inbound and outbound traffic for which the ALG is acting as an intermediary or proxy must be denied by default.

Check Content

Verify the ALG denies network communications traffic by default and allows network communications traffic by exception on both inbound and outbound interfaces. If the ALG does not deny network communications traffic by default and allow network communications traffic by exception on both inbound and outbound interfaces, this is a finding.

Fix Text

Configure the ALG to deny network communications traffic by default and allow network communications traffic by exception on both inbound and outbound interfaces.

Additional Identifiers

Rule ID: SV-68887r1_rule

Vulnerability ID: V-54641

Group Title: SRG-NET-000202-ALG-000124

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.