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TI-2021-04344 Aliases CVE-2021-21241GHSA-hh7m-rx4f-4vpv

CSRF can expose users authentication token in Flask-Security-Too

Priority LOW 34CWE-352Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Tampering
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-352.

Summary

The Python "Flask-Security-Too" package is used for adding security features to your Flask application. It is an is a independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. In Flask-Security-Too from version 3.3.0 and before version 3.4.5, the /login and /change endpoints can return the authenticated user's authentication token in response to a GET request. Since GET requests aren't protected with a CSRF token, this could lead to a malicious 3rd party site acquiring the authentication token. Version 3.4.5 and version 4.0.0 are patched. As a workaround, if you aren't using authentication tokens - you can set the SECURITY_TOKEN_MAX_AGE to "0" (seconds) which should make the token unusable.

Why it matters now

EPSS 0.00928 60th percentileScored 2026-11-07
Fix Fixed flask-security-too (Flask-Middleware): 3.4.5Flask-Security-Too (PyPI): 3.4.5

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
Flask-Middlewareflask-security-too3.3.0 to before 3.4.53.4.5Patch availableCNA
—Flask-Security-Too (PyPI)3.3.0 to before 3.4.53.4.5Patch availableGHSA-hh7m-rx4f-4vpv
  • flask-security-too VendorFlask-Middleware Affected 3.3.0 to before 3.4.5 Fixed in 3.4.5 Patch available CNA
  • Flask-Security-Too (PyPI) Vendor— Affected 3.3.0 to before 3.4.5 Fixed in 3.4.5 Patch available GHSA-hh7m-rx4f-4vpv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:flask-security-too_project:flask-security-too:*:*:*:*:*:*:*:*3.3.0 to before 3.4.5VulnerableFlask-security-too Project
  • cpe:2.3:a:flask-security-too_project:flask-security-too:*:*:*:*:*:*:*:* Versions 3.3.0 to before 3.4.5 Vulnerable ·Flask-security-too Project

Remediation

  • Fix · CNA flask-security-too (Flask-Middleware) Fixed in 3.4.5
  • Fix · GHSA-hh7m-rx4f-4vpv Flask-Security-Too (PyPI) Fixed in 3.4.5 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-21241
  2. 2026-10-03 Alias added: GHSA-hh7m-rx4f-4vpv

References

  • TI-2023-27010 An open redirect vulnerability in the python package Flask-Security-Too <=5.3.2 allows… CVSS 3.1MEDIUM 6.1

Sources