Risk Level: High
Cloud Entity: Application Load Balancer
CloudGuard Rule ID: D9.AWS.NET.AG2.8.ApplicationLoadBalancer.138.UDP
Covered by Spectral: No
Category: Networking & Content Delivery
ApplicationLoadBalancer where isPublic=true and nics contain [ subnet.routeTable.associations length()>0 ] and nics contain [ subnet.routeTable.routes contain [ destinationCidrBlock='0.0.0.0/0' and gatewayId regexMatch /gw/ ] ] should not have inboundRules contain [ port<=138 and portTo>=138 and protocol in ('UDP', 'ALL') and scope isPublic() and scope='0.0.0.0/0']
Limit the access scope for ApplicationLoadBalancer with service 'NetBios Datagram Service to only allow access in internal networks and limited scope.
If public interface exists, remove it and limit the access scope within the VPC only to applications or instances that requires access.
As a further protection step, Use CloudGuard 'Tamper Protection' (Full Protection mode) and region lock to prevent unauthorized changes to network access settings, refer to https://sc1.checkpoint.com/documents/CloudGuard_Dome9/Documentation/Network-Security/DynAccessLease.html?Highlight=dynamic%20access for more details.
An Application Load Balancer functions at the application layer, the seventh layer of the Open Systems Interconnection (OSI) model. After the load balancer receives a request, it evaluates the listener rules in priority order to determine which rule to apply, and then selects a target from the target group for the rule action. You can configure listener rules to route requests to different target groups based on the content of the application traffic. Routing is performed independently for each target group, even when a target is registered with multiple target groups.
Updated 16 days ago