BSides Toronto 2020

Subdomain takeovers and how to prevent them
2020-10-18, 11:30–11:50, Twitch

Did you know that taking over a subdomain is a pretty easy thing to do if you know what you're looking for?
Did you know that these types of attacks have caused millions of dollars in damage?
How do they happen, and how can we prevent them?


At Auth0 we own and operate a large number of subdomains. These are often being reconfigured, changed and if done incorrectly, they can lead to a "subdomain takeover" where an attacker can become the owner of the subdomain without you knowing and continue to use the domain for other attacks such as phishing. What is a subdomain attack, why does it happen and how can we prevent it?!

Matthew Marji is a Senior Product Security engineer for Auth0, an identity platform for application builders. He possesses the natural ability to simplify difficult security concepts; empowering the engineering teams he works with to build secure applications. In his free time, he lifts weights, enjoys espresso, and reads the OAuth2 RFC.