lacework-global-571

6.4 Evaluate and restrict HTTP(S) access from the Internet (Automated)

Profile Applicability

• Level 1

Description

Network security groups should be periodically evaluated for port misconfigurations. If a network security group exposes certain ports and protocols to the Internet, evaluate them for necessity and restrict 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.

Audit

From Azure Portal

1. For each VM, open the Networking blade
2. Verify that the INBOUND PORT RULES does not have a rule for HTTP such as
   • port = 80,
   • protocol = TCP,
   • Source = Any OR Internet

Using Azure Command Line Interface 2.0

List Network security groups with corresponding non-default Security rules:

az network nsg list --query [*].[name,securityRules]

Ensure that none of the NSGs have security rule as below

"access" : "Allow"
"destinationPortRange" : "80" or "*" or "[port range containing 80]"
"direction" : "Inbound"
"protocol" : "TCP"
"sourceAddressPrefix" : "*" or "0.0.0.0" or "<nw>/0" or "/0" or "internet" or "any"

Remediation

Where HTTP(S) is not explicitly required and narrowly configured for resources attached to the Network Security Group, restrict or eliminate Internet-level access to your Azure resources.

For internal access to relevant resources, configure an encrypted network tunnel such as:

ExpressRoute

Site-to-site VPN

Point-to-site VPN

References

Express Route
https://docs.microsoft.com/en-us/azure/expressroute/
Site-to-Site VPN
https://docs.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-howto-site-to-site-resource-manager-portal
Point-to-Site VPN
https://docs.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-howto-point-to-site-resource-manager-portal
https://docs.microsoft.com/en-us/security/benchmark/azure/security-controls-v3-network-security#ns-1-establish-network-segmentation-boundaries