Mutelisting¶

Sometimes you may find resources that are intentionally configured in a certain way that may be a bad practice but it is all right with it, for example an AWS S3 Bucket open to the internet hosting a web site, or an AWS Security Group with an open port needed in your use case.

Mutelist option works along with other options and will modify the output in the following way if the finding is muted:

JSON-OCSF: status_id is Suppressed.
CSV: muted is True. The field status will keep the original status, MANUAL, PASS or FAIL, of the finding.

You can use -w/--mutelist-file with the path of your mutelist yaml file:

prowler <provider> -w mutelist.yaml

Mutelist YAML File Syntax¶

Note

For Azure provider, the Account ID is the Subscription Name and the Region is the Location.

Note

For GCP provider, the Account ID is the Project ID and the Region is the Zone.

Note

For Kubernetes provider, the Account ID is the Cluster Name and the Region is the Namespace.

The Mutelist file is a YAML file with the following syntax:

    ### Account, Check and/or Region can be * to apply for all the cases.
    ### Resources and tags are lists that can have either Regex or Keywords.
    ### Tags is an optional list that matches on tuples of 'key=value' and are "ANDed" together.
    ### Use an alternation Regex to match one of multiple tags with "ORed" logic.
    ### For each check you can except Accounts, Regions, Resources and/or Tags.
    ###########################  MUTELIST EXAMPLE  ###########################
    Mutelist:
      Accounts:
        "123456789012":
          Checks:
            "iam_user_hardware_mfa_enabled":
              Regions:
                - "us-east-1"
              Resources:
                - "user-1"           # Will ignore user-1 in check iam_user_hardware_mfa_enabled
                - "user-2"           # Will ignore user-2 in check iam_user_hardware_mfa_enabled
            "ec2_*":
              Regions:
                - "*"
              Resources:
                - "*"                 # Will ignore every EC2 check in every account and region
            "*":
              Regions:
                - "*"
              Resources:
                - "test"
              Tags:
                - "test=test"         # Will ignore every resource containing the string "test" and the tags 'test=test' and
                - "project=test|project=stage" # either of ('project=test' OR project=stage) in account 123456789012 and every region

        "*":
          Checks:
            "s3_bucket_object_versioning":
              Regions:
                - "eu-west-1"
                - "us-east-1"
              Resources:
                - "ci-logs"           # Will ignore bucket "ci-logs" AND ALSO bucket "ci-logs-replica" in specified check and regions
                - "logs"              # Will ignore EVERY BUCKET containing the string "logs" in specified check and regions
                - ".+-logs"           # Will ignore all buckets containing the terms ci-logs, qa-logs, etc. in specified check and regions
            "ecs_task_definitions_no_environment_secrets":
              Regions:
                - "*"
              Resources:
                - "*"
              Exceptions:
                Accounts:
                  - "0123456789012"
                Regions:
                  - "eu-west-1"
                  - "eu-south-2"        # Will ignore every resource in check ecs_task_definitions_no_environment_secrets except the ones in account 0123456789012 located in eu-south-2 or eu-west-1
            "*":
              Regions:
                - "*"
              Resources:
                - "*"
              Tags:
                - "environment=dev"    # Will ignore every resource containing the tag 'environment=dev' in every account and region

        "123456789012":
          Checks:
            "*":
              Regions:
                - "*"
              Resources:
                - "*"
              Exceptions:
                Resources:
                  - "test"
                Tags:
                  - "environment=prod"   # Will ignore every resource except in account 123456789012 except the ones containing the string "test" and tag environment=prod

AWS Mutelist¶

Mute specific AWS regions¶

If you want to mute failed findings only in specific regions, create a file with the following syntax and run it with prowler aws -w mutelist.yaml:

Mutelist:
  Accounts:
  "*":
    Checks:
      "*":
        Regions:
          - "ap-southeast-1"
          - "ap-southeast-2"
        Resources:
          - "*"

Default Mutelist¶

For the AWS Provider, Prowler is executed with a Default AWS Mutelist with the AWS Resources that should be muted such as all resources created by AWS Control Tower when setting up a landing zone. You can see this Mutelist file in prowler/config/aws_mutelist.yaml.

Supported Mutelist Locations¶

The mutelisting flag supports the following AWS locations when using the AWS Provider:

AWS S3 URI¶

You will need to pass the S3 URI where your Mutelist YAML file was uploaded to your bucket:

prowler aws -w s3://<bucket>/<prefix>/mutelist.yaml

Note

Make sure that the used AWS credentials have s3:GetObject permissions in the S3 path where the mutelist file is located.

AWS DynamoDB Table ARN¶

You will need to pass the DynamoDB Mutelist Table ARN:

prowler aws -w arn:aws:dynamodb:<region_name>:<account_id>:table/<table_name>

The DynamoDB Table must have the following String keys:
The Mutelist Table must have the following columns:
- Accounts (String): This field can contain either an Account ID or an * (which applies to all the accounts that use this table as an mutelist).
- Checks (String): This field can contain either a Prowler Check Name or an * (which applies to all the scanned checks).
- Regions (List): This field contains a list of regions where this mutelist rule is applied (it can also contains an * to apply all scanned regions).
- Resources (List): This field contains a list of regex expressions that applies to the resources that are wanted to be muted.
- Tags (List): -Optional- This field contains a list of tuples in the form of 'key=value' that applies to the resources tags that are wanted to be muted.
- Exceptions (Map): -Optional- This field contains a map of lists of accounts/regions/resources/tags that are wanted to be excepted in the mutelist.

The following example will mute all resources in all accounts for the EC2 checks in the regions eu-west-1 and us-east-1 with the tags environment=dev and environment=prod, except the resources containing the string test in the account 012345678912 and region eu-west-1 with the tag environment=prod:

Note

Make sure that the used AWS credentials have dynamodb:PartiQLSelect permissions in the table.

AWS Lambda ARN¶

You will need to pass the AWS Lambda Function ARN:

prowler aws -w arn:aws:lambda:REGION:ACCOUNT_ID:function:FUNCTION_NAME

Make sure that the credentials that Prowler uses can invoke the Lambda Function:

- PolicyName: GetMuteList
  PolicyDocument:
    Version: '2012-10-17'
    Statement:
      - Action: 'lambda:InvokeFunction'
        Effect: Allow
        Resource: arn:aws:lambda:REGION:ACCOUNT_ID:function:FUNCTION_NAME

The Lambda Function can then generate an Mutelist dynamically. Here is the code an example Python Lambda Function that generates an Mutelist:

def handler(event, context):
  checks = {}
  checks["vpc_flow_logs_enabled"] = { "Regions": [ "*" ], "Resources": [ "" ], Optional("Tags"): [ "key:value" ] }

  al = { "Mutelist": { "Accounts": { "*": { "Checks": checks } } } }
  return al