Remediation

From Google Cloud Console

1. Go to VPC Network.
2. Go to the Firewall Rules.
3. Click the Firewall Rule to be modified.
4. Click Edit.
5. Modify Source IP ranges to specific IP.
6. Click Save.

From Google Cloud CLI

1. Identify Firewall Rules Allowing Public Access

   gcloud compute networks get-effective-firewalls default \
       --format="table(NAME, DIRECTION, IP_RANGES)" \
       --filter="IP_RANGES:0.0.0.0/0 AND DIRECTION:INGRESS"

2. Restrict the Source Range

   Once you have identified the firewall rules, update each one to restrict access to trusted CIDR ranges:

   gcloud compute firewall-rules update {{firewall-rule-name}} \
       -allow=[{{tcp:80-80}},{{icmp}}] \
       --source-ranges={{cidr-range1}},{{cidr-range2}}