https://infosecwriteups.com/fastly-subdomain-takeover-2000-217bb180730f
1. whois
2. history
CONFIRMING THE VULNERABILITY I went to Fastly official website and performed below steps, 1. I created an account on fastly.com using a temporary mail. 2. Logged in to my Fastly Dashboard and clicked on the “Create a Delivery Service” button. 3. Entered target subdomain name(next.redacted.com) and clicked on Add button. I was expecting the error message (“domain is already taken by another customer”) to appear but there was no error message. I was redirected to the next page “Hosts page”. I was surprised.