CVE-2021-23401
MEDIUMFlask-User - Open Redirect via URL Validation Bypass
Title source: llmDescription
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.
References (3)
Core 3
Core References
Third Party Advisory x_refsource_misc
https://snyk.io/vuln/SNYK-PYTHON-FLASKUSER-1293188
Product, Third Party Advisory x_refsource_misc
https://github.com/lingthio/Flask-User
Exploit, Third Party Advisory x_refsource_misc
https://github.com/lingthio/Flask-User/blob/master/flask_user/user_manager__utils.py
Scores
CVSS v3
5.4
EPSS
0.0111
EPSS Percentile
61.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Details
CWE
CWE-601
Status
published
Products (2)
flask-user_project/flask-user
pypi/Flask-User
0PyPI
Published
Jul 05, 2021
Tracked Since
Feb 18, 2026