S3 buckets audit: check bucket's public access level, etc .. updated with authorised audit support

I previous post: S3 buckets audit: check bucket existence, public access level, etc - without having access to target AWS account I described and released tool to audit s3 buckets even without access to the AWS account these buckets belong to.

But what about if I have access to the bucket's account or I would like to audit all buckets in my AWS account?

These features have been addressed in the new release of the s3 audit tool:

https://github.com/IhorKravchuk/it-security/tree/master/scripts.aws

$python aws_test_bucket.py --profile prod-read --bucket bucket2test

$python aws_test_bucket.py --profile prod-read --file aws

$python aws_test_bucket.py --profile prod-read --file buckets.list

  -P AWS_PROFILE, --profile=AWS_PROFILE
                        Please specify AWS CLI profile
  -B BUCKET, --bucket=BUCKET
                        Please provide bucket name
  -F FILE, --file=FILE  Optional: file with buckets list to check or aws to check all buckets in your account

Note:

--profile=AWS_PROFILE - yours AWS access profile (from aws cli). This profile  might or might not have access to the audited bucket (we need this just to become Authenticated User from AWS point of view ).

If  AWS_PROFILE allows authorised access to the bucket being audited - tool will fetch bucket's ACLs, Policies and S3 Static Web setting and perform authorised audit.

If AWS_PROFILE does not allow authorised access - tool will work in pentester mode

You can specify:

•  one bucket to check using --bucket option
•  file with list of buckets(one bucket name per line) using --file option
•  all buckets in your AWS account (accessible using AWS_PROFILE) using --file=aws option

Based on the your AWS profile limitations tool will provide you:

• indirect scan results (AWS_profile have no API access to the bucket being audited)
• validated scan results based on you s3 buckets settings like ACL, bucket policy and s3 website config. (AWS_profile have API access to the bucket being audited )

Enjoy and stay secured.

PS. Currently tool does not support bucket check for Frankfurt region (AWS Signature Version 4). Working on it.

S3 buckets audit: check bucket existence, public access level, etc - without having access to target AWS account

      Currently, publicly accessible buckets become a big deal and root cause of many recent data leaks.
All of these events even drive Amazon AWS to proactively send out emails to the customers who has such s3 configurations. Let's become a bit more proactive as well and audit s3 buckets

        First, let's take look why bucket might become publicly available:
- Configured for public access intentionally (S3 static web hosting or just public resource) or by mistake
- Configured for the access of the Authenticated Users  (option, misinterpreted by many as users from your account, which is wrong, it's any AWS authenticated user from any account)
     
         Auditing AWS account you have full access to is quite easy - just list the buckets and check theirs ACL, users and bucket policies via aws cli or web gui.

         What about cases when you:
- have many accounts and buckets (will take forever to audit manually)
- do not have enough permissions in the target AWS account to check bucket access
- you do not have permissions at all in this account (pentester mode)

To address everything above I've created small tool to do all dirty job for you (updated to v2):
https://github.com/IhorKravchuk/it-security/tree/master/scripts.aws


$python aws_test_bucket.py --profile prod-read --bucket test.bcuket

  -P AWS_PROFILE, --profile=AWS_PROFILE
                        Please specify AWS CLI profile
  -B BUCKET, --bucket=BUCKET
                        Please provide bucket name
  -F FILE, --file=FILE  Optional: file with buckets list to check

Note: --profile=AWS_PROFILE - any your AWS access profile (from aws cli). This profile HAS to NOT have access to the audited bucket (we need this just to become Authenticated User from AWS point of view )

You can specify one bucket to check using --bucket option or file with list of buckets(one bucket name per line) using --file option

Based on the bucket access status tool will provide you following responses:

Bucket: test.bucktet - The specified bucket does not exist

Bucket: test.bucktet -  Bucket exists, but Access Denied

Bucket: test.bucktet -  Found index.html, most probably S3 static web hosting is enabled

Bucket: test.bucktet - Bucket exists, publicly available and no S3 static web hosting, most probably misconfigured! 

Enjoy!

PS. More over, you can create list of the buckets(even using some DNS/name alterations and permutations) to test in the file and loop through it checking each.

Stay secure.