Public ApplicationLoadBalancer with service 'NetBIOS Name Service' (UDP:137) is exposed to the entire internet
Services and databases store data that may be sensitive, protected by law, subject to regulatory requirements or compliance standards. It is highly recommended that access to data will be restricted to encrypted protocols. This rule detects network settings that may expose data via unencrypted protocol over the public internet or to a too wide local scope.
Risk Level: High
Cloud Entity: Application Load Balancer
CloudGuard Rule ID: D9.AWS.NET.AG2.8.ApplicationLoadBalancer.137.UDP
Covered by Spectral: No
Category: Networking & Content Delivery
GSL LOGIC
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<=137 and portTo>=137 and protocol in ('UDP', 'ALL') and scope isPublic() and scope='0.0.0.0/0']
REMEDIATION
Limit the access scope for ApplicationLoadBalancer with service 'NetBIOS Name 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.
Amazon Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/authorizing-access-to-an-instance.html
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.
Application Load Balancer
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.
Compliance Frameworks
- BP-0318
- LGPD
- NETWSEC-V2
Updated over 1 year ago