Description

GCP Firewall Rules are specific to a VPC Network. Each rule either allows or denies traffic when its conditions are met. Its conditions allow users to specify the type of traffic, such as ports and protocols, and the source or destination of the traffic, including IP addresses, subnets, and instances. More details can be found in https://cloud.google.com/vpc/docs/firewalls

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  Recommended Mitigation

  Ensure vpc firewall rule in your account are configured to allow access to TCP port 139 and UDP ports 137, 138 (NetBIOS) and 139, 445 (SMB) from specific IP addresses only.