Description 


By allowing public access (from IP 0.0.0.0/0)  over the internet to SSH ports you are allowing attackers all over the internet to access your virtual machines and servers and attempt exploitation of known vulnerabilities in operating systems or use brute force techniques to gain access to servers, data, and information systems.


Remediation 

Azure Portal

  1. Go to Azure Portal 
  2. Select Network Security Groups under resources
  3. Go to Security Group (or all groups one at a time)
  4. Under Settings->Inbound Security Rules
  5. On the right-hand pane, review the list of security rules
  6. Remove or update any inbound rule where incoming / ingress traffic is allowed from source IP '0.0.0.0/0' and destination port is 22 with protocol TCP.


Additional documents 

https://docs.microsoft.com/en-us/azure/virtual-network/network-security-groups-overview