CloudWatch IAM Policy Changes Alarm Missing

Query id: eaaba502-2f94-411a-a3c2-83d63cc1776d
Query name: CloudWatch IAM Policy Changes Alarm Missing
Platform: Terraform
Severity: High
Category: Observability
URL: Github

Description¶

Ensure a log metric filter and alarm exist for IAM policy changes
Documentation

Code samples¶

Code samples with security vulnerabilities¶

Positive test num. 1 - tf file

provider "aws" {
  region = "us-east-2"
}

resource "aws_cloudwatch_log_group" "CIS_CloudWatch_LogsGroup" {
  name = "CIS_CloudWatch_LogsGroup"
}

resource "aws_sns_topic" "cis_alerts_sns_topic" {
  name = "cis-alerts-sns-topic"
}

resource "aws_cloudwatch_metric_alarm" "cis_iam_policy_change" {
  alarm_name                = "CIS-4.4-IAM-Policy-Change"
  comparison_operator       = "GreaterThanOrEqualToThreshold"
  evaluation_periods        = "1"
  metric_name               = "XXXX NOT YOUR FILTER XXXX"
  namespace                 = "CIS_Metric_Alarm_Namespace"
  period                    = "300"
  statistic                 = "Sum"
  threshold                 = "1"
  alarm_actions             = [aws_sns_topic.cis_alerts_sns_topic.arn]
  insufficient_data_actions = []
}

resource "aws_cloudwatch_log_metric_filter" "cis_iam_policy_change" {
  name           = "CIS-4.4-IAM-Policy-Change"
  pattern        = "{($.eventName=DeleteGroupPolicy)||($.eventName=DeleteRolePolicy)||($.eventName=DeleteUserPolicy)||($.eventName=PutGroupPolicy)||($.eventName=PutRolePolicy)||($.eventName=PutUserPolicy)||($.eventName=CreatePolicy)||($.eventName=DeletePolicy)||($.eventName=CreatePolicyVersion)||($.eventName=DeletePolicyVersion)||($.eventName=AttachRolePolicy)||($.eventName=DetachRolePolicy)||($.eventName=AttachUserPolicy)||($.eventName=DetachUserPolicy)||($.eventName=AttachGroupPolicy)||($.eventName=DetachGroupPolicy)}"
  log_group_name = aws_cloudwatch_log_group.CIS_CloudWatch_LogsGroup.name

  metric_transformation {
    name      = "CIS-4.4-IAM-Policy-Change"
    namespace = "CIS_Metric_Alarm_Namespace"
    value     = "1"
  }
}

Positive test num. 2 - tf file

provider "aws" {
  region = "us-east-2"
}

resource "aws_cloudwatch_log_group" "CIS_CloudWatch_LogsGroup" {
  name = "CIS_CloudWatch_LogsGroup"
}

resource "aws_sns_topic" "cis_alerts_sns_topic" {
  name = "cis-alerts-sns-topic"
}

resource "aws_cloudwatch_metric_alarm" "cis_iam_policy_change" {
  alarm_name                = "CIS-4.4-IAM-Policy-Change"
  comparison_operator       = "GreaterThanOrEqualToThreshold"
  evaluation_periods        = "1"
  metric_name               = aws_cloudwatch_log_metric_filter.cis_iam_policy_change.id
  namespace                 = "CIS_Metric_Alarm_Namespace"
  period                    = "300"
  statistic                 = "Sum"
  threshold                 = "1"
  alarm_actions             = [aws_sns_topic.cis_alerts_sns_topic.arn]
  insufficient_data_actions = []
}

resource "aws_cloudwatch_log_metric_filter" "cis_iam_policy_change" {
  name           = "CIS-4.4-IAM-Policy-Change"
  pattern        = "{($.eventName=DeleteRolePolicy)||($.eventName=DeleteUserPolicy)||($.eventName=PutGroupPolicy)||($.eventName=PutRolePolicy)||($.eventName=PutUserPolicy)||($.eventName=CreatePolicy)||($.eventName=DeletePolicy)||($.eventName=CreatePolicyVersion)||($.eventName=DeletePolicyVersion)||($.eventName=AttachRolePolicy)||($.eventName=DetachRolePolicy)||($.eventName=AttachUserPolicy)||($.eventName=DetachUserPolicy)||($.eventName=AttachGroupPolicy)||($.eventName=DetachGroupPolicy)}"
  log_group_name = aws_cloudwatch_log_group.CIS_CloudWatch_LogsGroup.name

  metric_transformation {
    name      = "CIS-4.4-IAM-Policy-Change"
    namespace = "CIS_Metric_Alarm_Namespace"
    value     = "1"
  }
}

Code samples without security vulnerabilities¶

Negative test num. 1 - tf file

provider "aws" {
  region = "us-east-2"
}

resource "aws_cloudwatch_log_group" "CIS_CloudWatch_LogsGroup" {
  name = "CIS_CloudWatch_LogsGroup"
}

resource "aws_sns_topic" "cis_alerts_sns_topic" {
  name = "cis-alerts-sns-topic"
}

resource "aws_cloudwatch_metric_alarm" "cis_iam_policy_change" {
  alarm_name                = "CIS-4.4-IAM-Policy-Change"
  comparison_operator       = "GreaterThanOrEqualToThreshold"
  evaluation_periods        = "1"
  metric_name               = aws_cloudwatch_log_metric_filter.cis_iam_policy_change.id
  namespace                 = "CIS_Metric_Alarm_Namespace"
  period                    = "300"
  statistic                 = "Sum"
  threshold                 = "1"
  alarm_actions             = [aws_sns_topic.cis_alerts_sns_topic.arn]
  insufficient_data_actions = []
}

resource "aws_cloudwatch_log_metric_filter" "cis_iam_policy_change" {
  name           = "CIS-4.4-IAM-Policy-Change"
  pattern        = "{($.eventName=DeleteGroupPolicy)||($.eventName=DeleteRolePolicy)||($.eventName=DeleteUserPolicy)||($.eventName=PutGroupPolicy)||($.eventName=PutRolePolicy)||($.eventName=PutUserPolicy)||($.eventName=CreatePolicy)||($.eventName=DeletePolicy)||($.eventName=CreatePolicyVersion)||($.eventName=DeletePolicyVersion)||($.eventName=AttachRolePolicy)||($.eventName=DetachRolePolicy)||($.eventName=AttachUserPolicy)||($.eventName=DetachUserPolicy)||($.eventName=AttachGroupPolicy)||($.eventName=DetachGroupPolicy)}"
  log_group_name = aws_cloudwatch_log_group.CIS_CloudWatch_LogsGroup.name

  metric_transformation {
    name      = "CIS-4.4-IAM-Policy-Change"
    namespace = "CIS_Metric_Alarm_Namespace"
    value     = "1"
  }
}