Information
Security groups provide stateful filtering of ingress and egress network traffic to AWS resources. It is recommended that no security group allows unrestricted ingress access to remote server administration ports, such as SSH to port 22 and RDP to port 3389.
Rationale:
Public access to remote server administration ports, such as 22 and 3389, increases resource attack surface and unnecessarily raises the risk of resource compromise.
Impact:
When updating an existing environment, ensure that administrators have access to remote server administration ports through another mechanism before removing access by deleting the 0.0.0.0/0 inbound rule.
Solution
Perform the following to implement the prescribed state:
Login to the AWS Management Console at https://console.aws.amazon.com/vpc/home
In the left pane, click Security Groups
For each security group, perform the following:
Select the security group
Click the Inbound Rules tab
Click the Edit inbound rules button
Identify the rules to be edited or removed
Either A) update the Source field to a range other than 0.0.0.0/0, or, B) Click Delete to remove the offending inbound rule
Click Save rules