Open Redirect in Flask-Security Project

CVE-2021-23385

This affects all versions of package Flask-Security. When using the get_post_logout_redirect and get_post_login_redirect functions, 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. 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. **Note:** Flask-Security is not maintained anymore.

Vulnerability class: Open Redirect

EPSS: 0.009 (56.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-23385?
CVE-2021-23385 is a medium-severity vulnerability in Flask-Security Project, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.4/10. Published 2022-08-02.
How severe is CVE-2021-23385?
Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2021-23385 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.