The $68 Million Mistake That Was Entirely Preventable
In 2019, the Capital One breach exposed the personal data of over 100 million people. A former AWS employee exploited a misconfigured web application firewall to access an AWS metadata endpoint. From there, she obtained IAM credentials that gave full access to Capital One's S3 buckets — where customer data sat in plaintext.
The misconfiguration: a single server role had been given excessive permissions, and a firewall was configured to allow outbound requests it should have blocked. Two configuration mistakes. $270M in fines, settlements, and remediation costs.
What all of these have in common: no custom exploit, no zero-day, no sophisticated technique. Someone left a door open. Someone else walked through it.
What made the Capital One breach a misconfiguration issue rather than a vulnerability in custom code?