Advanced Case Study: $10,000 for a Misconfigured S3 Buc

Advanced Case Study: $10,000 for a Misconfigured S3 Bucket
Cloud misconfigurations are goldmines for bug bounty hunters. Let’s see how one open S3 bucket → critical impact → $10,000 reward.

Recon Phase​

Researcher started with subdomain enumeration:
subfinder -d company.com -o subdomains.txt
Found:
assets.company.com
When checking the DNS → it pointed to an Amazon S3 bucket.

Testing the Bucket​

Step 1: Check if the bucket is public
aws s3 ls s3://company-bucket-name
Output showed multiple files → publicly accessible
Step 2: Download contents
aws s3 sync s3://company-bucket-name ./loot
Now the hunter had all files locally.

What He Found​

Inside the bucket:
product_images/ → harmless
invoices/ → contained customer billing details
config/production.env → contained:
DB_USER=admin
DB_PASS=SuperSecret123
AWS_ACCESS_KEY=AKIA****************
AWS_SECRET_KEY=*********************
This meant full database + cloud account compromise was possible.

Impact​

Attackers could use leaked AWS keys to:
Spin up servers at company’s expense
Access databases → steal/modify user data
Pivot into internal infrastructure
This was critical severity .

Bounty​

The hunter submitted a responsible disclosure with:
Steps to reproduce
Proof of exposed keys
Risk analysis
Company fixed the misconfiguration + rotated all keys.
Paid out $10,000 bounty

Lessons for Hunters​

Always check for S3 buckets, GCP buckets, Azure blobs
Use tools:
s3scanner --bucket company-bucket
cloud_enum -k company
Small buckets → Big findings (even 1 .env file = jackpot)

Lessons for Companies​

Make storage private by default
Monitor for public ACLs
Rotate credentials often
Use AWS Config / Security Hub for continuous monitoring

Pro Tip for Hunters:
Many hackers ignore cloud. If you focus here, you’ll face less competition + higher bounties .