Risk Level: High
Cloud Entity: Elastic Load Balancing (ELB)
CloudGuard Rule ID: D9.AWS.NET.AG2.3.ELB.139.UDP
Covered by Spectral: No
Category: Networking & Content Delivery
ELB 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<=139 and portTo>=139 and protocol in ('UDP', 'ALL') and scope isPublic() and scope numberOfHosts()>=32 ]
Limit the access scope for ELB with service 'NetBios Session 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, use CloudGuard Dynamic Access Leasing to limit access to SSH/Remote Desktop only from allowed sources and only when needed.
For more information please refer to: https://sc1.checkpoint.com/documents/CloudGuard_Dome9/Documentation/Network-Security/DynAccessLease.html?tocpath=Network%20Security%7C_____3
Elastic Load Balancing automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, and IP addresses. It can handle the varying load of your application traffic in a single Availability Zone or across multiple Availability Zones. Elastic Load Balancing offers three types of load balancers that all feature the high availability, automatic scaling, and robust security necessary to make your applications fault tolerant.
Updated 16 days ago