Control: Azure > CIS v5.0 > 7 - Networking Services > 7.03 - Ensure that UDP access from the Internet is evaluated and restricted

Configures auditing against a CIS Benchmark item.

Level: 1

Network security groups should be periodically evaluated for port misconfigurations. Where UDP is not explicitly required and narrowly configured for resources attached to a network security group, Internet-level access to Azure resources should be restricted or eliminated.

The potential security problem with broadly exposing UDP services over the Internet is that attackers can use DDoS amplification techniques to reflect spoofed UDP traffic from Azure Virtual Machines. The most common types of these attacks exploit exposed DNS, NTP, SSDP, SNMP, CLDAP, and other UDP-based services as amplification sources to disrupt services on other machines within the Azure Virtual Network, or even attack networked devices outside of Azure.