Gitlab is vulnerable to impersonation attacks due to broken links

How it was found

Good afternoon team,

#Vulnerability

There's a lot of possible attacks that can be carried out with broken external links as noted in this github post by edoverflow. https://gist.github.com/EdOverflow/24e0bb929169eb948bb7f3d0a2d5528f.

In this particular example I'm impersonating Ricardo who redesigned gitlabhq back in 2011.

#POC

Go to https://about.gitlab.com/2011/11/22/whats-next/ and Ricardo is hyperlinked to his github account. Well somewhere between 2011 and 2017 he decided to delete his profile.

Before - F218161

After - F218162

Ricardo is back with a malicious url that has been shortened using bit.ly. Shortening the link hides that it's malicious.

In conclusion I have taken over an embedded link inside the Gitlab.com domain. Please let me know if you have any questions. I am happy to help and will continue to look for broken links!