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How to Find AWS EC2 Flow Logging is not enabled in all VPCs

Problem​

VPC Flow Logs provide visibility into network traffic that traverses the VPC and can be used to detect anomalous traffic or insight during security workflows.

info

This security check is part of the CIS Amazon Web Services Benchmarks and is rated severity medium.

Prerequisites​

This guide assumes that you have already installed and configured Resoto to collect your AWS cloud resources.

Directions​

  1. Execute the following search command in Resoto Shell or Resoto UI:

    > search is(aws_vpc) with(empty, --> is(aws_ec2_flow_log))
    ​kind=aws_vpc, ..., region=resoto-poweruser
    ​kind=aws_vpc, ..., account=poweruser-team

  2. Pipe the search command into the dump command:

    > search is(aws_vpc) with(empty, --> is(aws_ec2_flow_log)) | dump
    ​reported:
    ​  id: /aws/ec2/123
    ​  name: some-name
    ​  ctime: '2022-12-05T22:53:14Z'
    ​  kind: aws_vpc
    ​  age: 2mo28d

    The command output will list the details of all non-compliant aws_vpc resources.

  3. Fix detected issues by following the remediation steps:

    Enable Flow Logs for packet Rejects of your VPCs.

    note

    Please refer to the AWS EC2 documentation for details.

Further Reading​