Security groups should restrict ingress traffic to specified IPv4 addresses
Description
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 (IPv4).
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:
A. Select the security group
B. Click the Inbound Rules tab
C. Click the Edit inbound rules button
D. Identify the rules to be edited or removed
E. Either update the Source field to a range other than 0.0.0.0/0, or click Delete to remove the offending inbound rule
F. Click Save rules
