CVE-2021-23401

This affects all versions of package Flask-User. When using the make_safe_url function, it is possible to bypass URL validation and redirect a user to an arbitrary URL by providing multiple back slashes such as /////evil.com/path or \evil.com/path. This vulnerability is only exploitable if an alternative WSGI server other than Werkzeug is used, or the default behaviour of Werkzeug is modified using ‘autocorrect_location_header=False.

Date published : 2021-07-05

https://github.com/lingthio/Flask-User

https://github.com/lingthio/Flask-User/blob/master/flask_user/user_manager__utils.py