RubyGems · Report #178409
Possible Subdomain Takeover at http://production.s3.rubygems.org/ pointing to Fastly
Validstatus
5upvotes
6 Mar 2017disclosed
Summary
A DNS record was found that was pointing to Fastly, but there was no Fastly service configured for this domain. We removed the record because it was not needed any longer. A subdomain takeover was not possible because although there was no service configured, we do have control of any subdomain of rubygems.org so another user would not be able to register it.
RubyGems is right, there was no way to properly takeover that domain, but I reported because no service was configured, and this could cause trouble in the future, at least if a bug appears in Fastly
How it was found
The write-up for this report has not been downloaded yet, or the program disclosed it without one. Read it on HackerOne.