Open redirect via redirect_to parameter in tumblr.com

How it was found

Summary:

URL redirection is sometimes used as a part of phishing attacks that confuse visitors about which web site they are visiting.

Platform(s) Affected:

Website

Steps To Reproduce:

1. open any browser
2. enter https://www.tumblr.com/logout?redirect_to=https://evil.com%5C%40www.tumblr.com

Supporting Material/References:

video attached

Impact

A remote attacker can redirect users from your website to a specified URL. This problem may assist an attacker to conduct phishing attacks, trojan distribution, spammers.