Control: SNS topic policies should prohibit subscription public access

powerpipe control run aws_compliance.control.sns_topic_policy_prohibit_subscription_access

powerpipe login
powerpipe control run aws_compliance.control.sns_topic_policy_prohibit_subscription_access --share

with wildcard_action_policies as (
  select
    topic_arn,
    count(*) as statements_num
  from
    aws_sns_topic,
    jsonb_array_elements(policy_std -> 'Statement') as s,
    jsonb_array_elements_text(s -> 'Action') as a
  where
    s ->> 'Effect' = 'Allow'
    and (
      ( s -> 'Principal' -> 'AWS') = '["*"]'
      or s ->> 'Principal' = '*'
    )
    and a in ('sns:subscribe', 'sns:receive')
    and s -> 'Condition' is null
  group by
    topic_arn
)
select
  t.topic_arn as resource,
  case
    when p.topic_arn is null then 'ok'
    else 'alarm'
  end as status,
  case
    when p.topic_arn is null then title || ' does not allow subscribe access without condition.'
    else title || ' contains ' || coalesce(p.statements_num,0) || ' statements that allows subscribe access without condition.'
  end as reason
  
  , t.region, t.account_id
from
  aws_sns_topic as t
  left join wildcard_action_policies as p on p.topic_arn = t.topic_arn;