cve/2021/CVE-2021-23401.md

CVE-2021-23401

Description

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.

POC

Reference

• https://snyk.io/vuln/SNYK-PYTHON-FLASKUSER-1293188

Github

No PoCs found on GitHub currently.