CVE-2021-23401 Information

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.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Reference

https://snyk.io/vuln/SNYK-PYTHON-FLASKUSER-1293188 https://github.com/lingthio/Flask-User https://github.com/lingthio/Flask-User/blob/master/flask_user/user_manager__utils.py 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.

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

REQUIRED

Confidentiality Impact

CHANGED

Integrity Impact

LOW

Availability Impact

LOW

Base Score

NONE

Base Severity

6.1