The Ultimate Guide to Hacking AWS S3: Find Vulnerable Buckets and Earn Big $$$$

Welcome to the Ultimate Guide on AWS S3 Buckets!

Hey there! I’m Nebty, and in this comprehensive guide, I’ll walk you through everything you need to know about Amazon S3 buckets — from setting them up to testing them for security issues. When I first started diving into S3, I found it pretty inconvenient to piece together the information from various sources, so I decided to put everything into one complete guide.

Here, you’ll find detailed instructions on:

How to set up your S3 bucketsHow to find and test for misconfigurationsThe best tools and techniques for recon and vulnerability scanningExploitation methods and automation strategies to scale your testing

If you find this guide useful, please consider subscribing and leaving a thumbs-up — your support keeps me fueled with coffee, and it means the world to me! Let’s dive in and get your AWS S3 skills to the next level.

Disclaimer: This article is intended solely for educational purposes in the field of information security. The author encourages readers to use the knowledge gained ethically and strictly within the law, only to protect and enhance information security. Any misuse of the information presented is unacceptable and may be prosecuted.

Amazon S3 (Simple Storage Service) is a cloud storage service provided by Amazon Web Services (AWS). It allows you to store and retrieve an unlimited amount of data, offering scalability and high availability. The data in S3 is organized into buckets, which are containers that hold files, images, videos, and other data. Think of S3 as your digital attic — only with way more space and less dust.

Key Features:

- Scalability and Availability: Store any amount of data with access from anywhere. Unlike your attic, it won’t collapse on you.
- Storage Structure: Data is stored as objects in buckets, organized using key prefixes. Just don’t throw everything in one giant bucket (we’re not hoarders here).
- Security: You can set access policies for individual objects or entire buckets. Only let the right people in, no uninvited guests!
- Common Use Cases: Backup, archiving, static website hosting, content distribution via Amazon CloudFront.

Useful Links:

- Detailed Explanation of AWS : Covers the basic principles and capabilities of S3.
- Guide to Setting Up an S3 Bucket: Step-by-step instructions on creating and configuring an S3 bucket for storing data.
- Real-world Use Cases for S3: Explore practical scenarios for backup and hosting.

These resources will help you understand S3 better and guide you in using it efficiently for your tasks.

To interact with AWS S3, you need to generate an AWS Access Keys. Here’s how to do it:

1. Log into AWS Management Console as root.
2. Open IAM (Identity and Access Management).
3. Add a new user: Choose Programmatic Access to allow API/CLI access.
4. Set permissions: Attach the necessary policies, such as `AmazonS3ReadOnlyAccess` for read-only access to S3.
5. Save your keys: After setup, save your Access Key ID and Secret Access Key securely. These will only be shown once — so don’t lose them like your car keys!

For a more detailed walkthrough, you can refer to this guide on how to generate AWS Access Keys.

If you’re conducting security testing or vulnerability assessments, you’ll need the appropriate permissions to interact with resources. For S3 bucket testing, consider the following:

AmazonS3FullAccess — Full access to S3. This permission is crucial for interacting with S3 buckets, including reading object lists, downloading/uploading objects, and checking configurations (ACL, CORS, encryption settings, etc.).AdministratorAccess — Full access to all AWS services. This grants comprehensive access to all AWS resources, including S3, EC2, RDS, Lambda, and IAM, but is generally overkill unless you’re testing multiple AWS services.IAMFullAccess — Full access to IAM. While it’s not necessary for testing S3 directly, having full IAM permissions can be useful for managing roles and policies if you’re testing bucket permissions or configuring other services.

For S3 testing, AmazonS3FullAccess is typically all you need. The other permissions are useful for broader testing across AWS services but are not required specifically for S3 bucket vulnerability assessments.

These permissions ensure you have full control over S3 resources, making them ideal for thorough security testing or exploitation of potential vulnerabilities.

Method 1: Google Dorks

Use Google search to find publicly accessible S3 buckets:

site:s3.amazonaws.com company.com
site:.s3.amazonaws.com "company"
site:amazonaws.com inurl:.s3.amazonaws.com company.com
site:s3.amazonaws.com intitle:index.of.bucket company.com

If you have no idea what this is, I advise you to read this article.

Method 2: Check HTTP Responses

Look for S3 bucket references in HTTP responses. You might find AWS S3 links in image or file URLs:

\.s3\.amazonaws\.com\/?

Also, look for these HTTP headers:

x-amz-bucket-region
x-amz-id-2
x-amz-request-id

Method 3: App Discovery

In web apps, open an image in a new tab and inspect the URL. Often, the structure `https://company-name.s3.amazonaws.com/image.png` reveals the bucket name. It’s like finding the secret passage in a mystery novel.

Method 4: Online Tools

1. GrayHat Warfare
2. OSINT.sh

Method 5: Bruteforce Tools

1. S3enum
2. Cloud_enum
3. S3 Bucket Finder
4. S3Scanner
5. Lazy S3

No, these aren’t names of superhero sidekicks — they’re tools that help you uncover S3 buckets. Use wisely!

Once you find an S3 bucket, it’s time to test it. Here are some basic commands for security testing:

1. List Objects in Public Buckets

Check if the bucket is publicly accessible:

aws s3 ls s3://<bucket_name> --no-sign-request

2. Download Objects

Verify if files are available for download:

aws s3 cp s3://<bucket_name>/<object_name> ./local_file --no-sign-request

Use recursion if you’re unsure which files are there:

aws s3 cp s3://<bucket_name>/ ./ --recursive --no-sign-request

3. Check Access Control List (ACL)

See who has access to the bucket:

aws s3api get-bucket-acl --bucket <bucket_name> --no-sign-request

4. Test CORS Settings

Check for misconfigured CORS settings that could lead to data leaks:

aws s3api get-bucket-cors --bucket <bucket_name> --no-sign-request

5. Check Website Hosting Configuration

Determine if the bucket is configured for static website hosting:

aws s3api get-bucket-website --bucket <bucket_name> --no-sign-request

6. List Object Versions (If Versioning is Enabled)

Check for old or deleted versions of objects:

aws s3api list-object-versions --bucket <bucket_name> --no-sign-request

7. Check for Encryption

Make sure data is encrypted:

aws s3api get-bucket-encryption --bucket <bucket_name> --no-sign-request

8. Test Write Permissions

Check if the bucket allows public uploads:

echo "Test file for S3 bucket" > test.txt
aws s3 cp ./test.txt s3://<bucket_name>/test.txt --no-sign-request

It’s like sending a postcard to an unguarded mailbox — only digital.

Important: I also want to say that it is worth trying these commands without ` — no-sign-request`

Searching for Open S3 Buckets

If you’re curious about more lesser-known techniques for searching exposed buckets, check out this detailed guide. It covers a variety of methods for unearthing those hidden treasures.

If you find multiple S3 buckets, you can automate the testing process with a simple script:

output_file="buckets.txt"
for i in $(cat buckets.txt); do
echo "---------------------------------" >> "$output_file"
echo "Bucket: $i" >> "$output_file"
echo "---------------------------------" >> "$output_file"
aws s3 cp ./test.txt s3://$i /test.txt --no-sign-request >> "$output_file"
echo "" >> "$output_file"
done

and instead of `aws s3 cp ./test.txt s3://$i /test.txt — no-sign-request` you can put any other command.

If you want to dive deeper into S3 bucket exploitation, here are some additional resources to explore:

Exploiting Abandoned Buckets (Bucket Takeover)2. Automating Testing for Misconfigured S3 Buckets3. Top 10 AWS Vulnerabilities with Practical ExamplesAlso a similar article that covers some issues not covered in this article.4. For an even more comprehensive guide for manual testing, check out this complete guide to hacking misconfigured AWS S3 buckets

Testing AWS S3 buckets for vulnerabilities is essential to safeguarding data and identifying potential risks in your AWS environment. By following the steps outlined in this guide, you’ll be well-equipped to uncover misconfigurations and boost security.

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Author: Nebty

alex122303q@gmail.com