Ensure HTTP(S) access from the Internet is evaluated and restricted

Overview

Network security groups should be periodically evaluated for port misconfigurations. Where certain ports and protocols may be exposed to the Internet, they should be evaluated for necessity and restricted wherever they are not explicitly required and narrowly configured.

Rationale

The potential security problem with using HTTP(S) over the Internet is that attackers can use various brute force techniques to gain access to Azure resources. Once the attackers gain access, they can use the resource as a launch point for compromising other resources within the Azure tenant.

Remediation guidance

Run the below command to list network security groups:

az network nsg list --subscription <subscription-id> --output table

For each network security group, run the below command to list the rules associated with the specified port:

az network nsg rule list --resource-group <resource-group> --nsg-name <nsg-name> --query "[?destinationPortRange=='80 or 443']"

Run the below command to delete the rule with:

Port = 80/443 OR [port range containing 80/443]
Protocol = TCP OR "*"
Source = Any (*) OR IP Addresses (0.0.0.0/0) OR Service Tag (Internet)
Action = Allow

az network nsg rule delete --resource-group <resource-group> --nsg-name <nsg-name> --name <rule-name>

Azure Portal (Asset-Level)

Open the affected resource from the finding details in Azure Portal.
Navigate to the relevant Security/Configuration/Networking blade.
Apply the control-specific secure setting.
Save and re-run the check.

Multiple Remediation Paths

Azure

SERVICE-WIDE (RECOMMENDED when many resources are affected): Assign Azure Policy initiatives at management group/subscription scope and trigger remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

ASSET-LEVEL: Apply the resource-specific remediation steps above to the listed non-compliant resources.

PREVENTIVE: Embed Azure Policy checks into landing zones and IaC workflows to block or auto-remediate drift.

References for Service-Wide Patterns

Azure Policy overview: https://learn.microsoft.com/en-us/azure/governance/policy/overview
Azure Policy remediation: https://learn.microsoft.com/en-us/azure/governance/policy/how-to/remediate-resources
Azure Policy initiative structure: https://learn.microsoft.com/en-us/azure/governance/policy/concepts/initiative-definition-structure

Operational Rollout Workflow

Use this sequence to reduce risk and avoid repeated drift.

1. Contain at Service-Wide Scope First (Recommended)

Azure: assign policy initiatives at management group/subscription scope and run remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

2. Remediate Existing Affected Assets

Execute the control-specific Console/CLI steps documented above for each flagged resource.
Prioritize internet-exposed and production assets first.

3. Validate and Prevent Recurrence

Re-scan after each remediation batch.
Track exceptions with owner and expiry date.
Add preventive checks in IaC/CI pipelines.

Query logic

These are the stored checks tied to this control.

Azure NSGs allowing HTTP(S) traffic

Connectors

Microsoft Azure

Covered asset types

SecurityGroup

Expected check: eq []

{
  securityGroups(
    where: {
      rules_SOME: {
        direction: "Inbound"
        action: "Allow"
        protocol: "TCP"
        AND: [
          {
            OR: [
              { sources_INCLUDES: "cidr:0.0.0.0/0" }
              { sources_INCLUDES: "cidr:::/0" }
              { sources_INCLUDES: "tag:Internet" }
              { sources: [] }
            ]
          }
          {
            OR: [
              { destFromPort_LTE: 80, destToPort_GTE: 80 }
              { destFromPort_LTE: 443, destToPort_GTE: 443 }
            ]
          }
        ]
      }
    }
  ) {
    ...AssetFragment
  }
}