AWS Config Rules for CIS AWS Foundations Benchmark Compliance

This module outputs a map of AWS Config Rules that should be in place as part of acheiving compliance with the CIS AWS Foundation Benchmak 1.2 standard. These rules are meant to be used as an input to the Cloud Posse AWS Config Module and are defined in the rules catalog.

Usage

Which Account(s) Should Rules Be Applied In

In general, these rules are meant to be enabled in every region of each of your accounts, with some exceptions noted below.

Controls You May Want to Disable

There are some controls that are part of the standard that should be disabled in certain scenarios.

CIS AWS Foundations Benchmark Control 2.7: Ensure CloudTrail logs are encrypted at rest using AWS KMS CMKs

When you are using a centralized CloudTrail account, you should only run this rule in the centralized account. The rule can be enabled in the centralized account by setting the is_logging_account variable to true and disabled in all other accounts by setting is_logging_account to false or omitting it as false is the default value.

CIS AWS Foundations Benchmark Controls 1.2-1.14, 1.16, 1.20, 1.22, and 2.5: Global Resources

These controls deal with ensuring various global resources, such as IAM Users, are configured in a way that aligns with the Benchmark. Since these resources are global, there is no reason to have AWS Config check them in each region. One region should be designated as the Global Region for AWS Config and checks for these controls should only be run in that region. This set of checks can be enabled in the Global Region by setting the is_global_resource_region to true and disabled in all other regions by setting is_global_resource_region to false or omitting it as false is the default value.

Parameter Overrides

You may also override the values any of the AWS Config Parameters set by the rules from our catalog by providing a map of maps to the parameter_overrides variable. The example below shows overriding the MaxPasswordAge of the iam-password-policy rule. The rule defaults to 90 days, while in this example we want to set it to 45 days.

IMPORTANT: The master branch is used in source just as an example. In your code, do not pin to master because there may be breaking changes between releases. Instead pin to the release tag (e.g. ?ref=tags/x.y.z) of one of our latest releases.

For a complete example, see examples/cis.

For automated tests of the complete example using bats and Terratest (which tests and deploys the example on AWS), see test.

module "cis_1_2_rules" {
  source = "cloudposse/config/aws//modules/cis-1-2-rules"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"


  is_global_resource_region = true
  is_logging_account       = true

  parameter_overrides = {
    "iam-password-policy": {
      "MaxPasswordAge": "45"
    }
  }
}

module "config" {
  source = "cloudposse/config/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"

  create_sns_topic = true
  create_iam_role  = true

  managed_rules = module.cis_1_2_rules.rules
  }
}

Requirements

Name	Version
terraform	>= 1.0
aws	>= 5.0
http	>= 3.4.1

Providers

Name	Version
aws	>= 5.0

Modules

Name	Source	Version
aws_config_rules_yaml_config	cloudposse/config/yaml	1.0.2
this	cloudposse/label/null	0.25.0
utils	cloudposse/utils/aws	1.0.0

Resources

Name	Type
aws_region.current	data source

Inputs

Name	Description	Type	Default	Required
additional_tag_map	Additional key-value pairs to add to each map in tags_as_list_of_maps. Not added to tags or id. This is for some rare cases where resources want additional configuration of tags and therefore take a list of maps with tag key, value, and additional configuration.	map(string)	{}	no
attributes	ID element. Additional attributes (e.g. workers or cluster) to add to id, in the order they appear in the list. New attributes are appended to the end of the list. The elements of the list are joined by the delimiter and treated as a single ID element.	list(string)	[]	no
cloudtrail_bucket_name	The name of the S3 bucket where CloudTrail logs are being sent. This is needed to comply with 2.6 of the Benchmark which states: Ensure S3 bucket access logging is enabled on the CloudTrail S3 bucket	string	n/a	yes
config_rules_paths	Set of PATH'es to files with config rules	set(string)	[ "../../catalog/cloudtrail.yaml", "../../catalog/cmk.yaml", "../../catalog/iam.yaml", "../../catalog/network.yaml", "../../catalog/vpc.yaml" ]	no
context	Single object for setting entire context at once. See description of individual variables for details. Leave string and numeric variables as null to use default value. Individual variable settings (non-null) override settings in context object, except for attributes, tags, and additional_tag_map, which are merged.	any	{ "additional_tag_map": {}, "attributes": [], "delimiter": null, "descriptor_formats": {}, "enabled": true, "environment": null, "id_length_limit": null, "label_key_case": null, "label_order": [], "label_value_case": null, "labels_as_tags": [ "unset" ], "name": null, "namespace": null, "regex_replace_chars": null, "stage": null, "tags": {}, "tenant": null }	no
delimiter	Delimiter to be used between ID elements. Defaults to - (hyphen). Set to "" to use no delimiter at all.	string	null	no
descriptor_formats	Describe additional descriptors to be output in the descriptors output map. Map of maps. Keys are names of descriptors. Values are maps of the form {<br/> format = string<br/> labels = list(string)<br/>} (Type is any so the map values can later be enhanced to provide additional options.) format is a Terraform format string to be passed to the format() function. labels is a list of labels, in order, to pass to format() function. Label values will be normalized before being passed to format() so they will be identical to how they appear in id. Default is {} (descriptors output will be empty).	any	{}	no
enabled	Set to false to prevent the module from creating any resources	bool	null	no
environment	ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'	string	null	no
id_length_limit	Limit id to this many characters (minimum 6). Set to 0 for unlimited length. Set to null for keep the existing setting, which defaults to 0. Does not affect id_full.	number	null	no
is_global_resource_region	Flag to indicate if this instance of AWS Config is being installed to monitor global resources (such as IAM). In order to save money, you can disable the monitoring of global resources in all but region. If this flag is set to true, then the config rules associated with global resources in the catalog (globalResource: true) will be installed. If false, they will not be installed.	bool	false	no
is_logging_account	Flag to indicate if this instance of AWS Config is being installed into a centralized logging account. If this flag is set to true, then the config rules associated with logging in the catalog (loggingAccountOnly: true) will be installed. If false, they will not be installed. installed.	bool	false	no
label_key_case	Controls the letter case of the tags keys (label names) for tags generated by this module. Does not affect keys of tags passed in via the tags input. Possible values: lower, title, upper. Default value: title.	string	null	no
label_order	The order in which the labels (ID elements) appear in the id. Defaults to ["namespace", "environment", "stage", "name", "attributes"]. You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present.	list(string)	null	no
label_value_case	Controls the letter case of ID elements (labels) as included in id, set as tag values, and output by this module individually. Does not affect values of tags passed in via the tags input. Possible values: lower, title, upper and none (no transformation). Set this to title and set delimiter to "" to yield Pascal Case IDs. Default value: lower.	string	null	no
labels_as_tags	Set of labels (ID elements) to include as tags in the tags output. Default is to include all labels. Tags with empty values will not be included in the tags output. Set to [] to suppress all generated tags. Notes: The value of the name tag, if included, will be the id, not the name. Unlike other null-label inputs, the initial setting of labels_as_tags cannot be changed in later chained modules. Attempts to change it will be silently ignored.	set(string)	[ "default" ]	no
name	ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'. This is the only ID element not also included as a tag. The "name" tag is set to the full id string. There is no tag with the value of the name input.	string	null	no
namespace	ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique	string	null	no
parameter_overrides	Map of parameters for interpolation within the YAML config templates For example, to override the maxCredentialUsageAge parameter in the access-keys-rotated.yaml rule, you would specify the following: parameter_overrides = { "access-keys-rotated" : { maxCredentialUsageAge : "120" } }	map(map(string))	{}	no
regex_replace_chars	Terraform regular expression (regex) string. Characters matching the regex will be removed from the ID elements. If not set, "/[^a-zA-Z0-9-]/" is used to remove all characters other than hyphens, letters and digits.	string	null	no
stage	ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'	string	null	no
support_policy_arn	The ARN of the IAM Policy required for compliance with 1.20 of the Benchmark, which states: Ensure a support role has been created to manage incidents with AWS Support AWS provides a support center that can be used for incident notification and response, as well as technical support and customer services. Create an IAM role to allow authorized users to manage incidents with AWS Support. By implementing least privilege for access control, an IAM role will require an appropriate IAM policy to allow support center access in order to manage incidents with AWS Support.	string	n/a	yes
tags	Additional tags (e.g. {'BusinessUnit': 'XYZ'}). Neither the tag keys nor the tag values will be modified by this module.	map(string)	{}	no
tenant	ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for	string	null	no

Outputs

Name	Description
rules	Enabled rules