Internet Bug Bounty: CVE-2022-45402: Apache Airflow: Open redirect during login

In Apache Airflow versions prior to 2.4.3, there was an open redirect in the webserver’s /login endpoint.

my initial email to [email protected]:

Hi,

In Apache Airflow, there is a parameter "next" on the Login page. And after a successful login, we're redirected to this parameter's value. 
I see there are some preventions for the open redirect bug. However, I can bypass these preventions using "/\google.com"

It seems this parameter accepts anything after the slash "/" character. And, browsers parse "/\" as "http://" in the location header.

For reproducing, you can try to login on the http://127.0.0.1:8080/login/?next=/\google.com

I tested this bug in the last version (v2.4.2)

Regards,
Bugra Eskici

Here is the email thread:
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Impact

Unvalidated URL redirection during login, can be used for phishing, etc.

Regards,
Bugra