Network misconfigurations

Azure Network Security Group allows unrestricted ICMP traffic from the Internet



The Internet Control Message Protocol (ICMP) is a supporting protocol in the Internet protocol suite. It is used by network devices, including routers, to send error messages and operational information indicating success or failure when communicating with another IP address. This protocol can be used by an adversary for gathering information and generating attacks e.g. ICMP Tunnelling, Smurf Attack, etc.. There is a rule configured in {AzureNetworkSecurityGroup} network security group, that allows all incoming ICMP traffic from the Internet. In order to keep security best practices and decrease the risk for malicious activities, you should restrict access to be only from allowed IP addresses.