CVE-2021-23401

Public Exploit
Open Redirect

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.

Category

5.4
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.27%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory snyk.io
Affected: n/a Flask-User
Published at:
Updated at:

References

Link Tags
https://snyk.io/vuln/SNYK-PYTHON-FLASKUSER-1293188 third party advisory
https://github.com/lingthio/Flask-User product third party advisory
https://github.com/lingthio/Flask-User/blob/master/flask_user/user_manager__utils.py third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2021-23401?
CVE-2021-23401 has been scored as a medium severity vulnerability.
How to fix CVE-2021-23401?
To fix CVE-2021-23401, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-23401 being actively exploited in the wild?
It is possible that CVE-2021-23401 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-23401?
CVE-2021-23401 affects n/a Flask-User.
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