CVE-2021-21241: CSRF can expose users authentication token

CVE-2021-21241 · Severity: low · CVSS 3.1 · Published 2021-01-11

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.

Technologies: Flask-Security-Too (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2021-21241 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2021-21241 being exploited in the wild.
How severe is CVE-2021-21241?
Low severity, with a CVSS score of 3.1, published 11 January 2021.
Which products and versions are affected?
Flask-Security-Too (PyPI) ECOSYSTEM:introduced=3.3.0,fixed=3.4.5, GIT:introduced=0,fixed=61d313150b5f620d0b800896c4f2199005e84b1f,fixed=6d50ee9169acf813257c37b75babe9c28e83542a|ECOSYSTEM:introduced=3.3.0,fixed=3.4.5.
Is there a fix for CVE-2021-21241?
Yes. Flask-Security-Too (PyPI): upgrade to 3.4.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2021-21241?
Check whether you run Flask-Security-Too (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Flask-Security-Too (PyPI): upgrade to 3.4.5 or later
    pip install "Flask-Security-Too>=3.4.5"

Affected products

  • Flask-Security-Too (PyPI) ECOSYSTEM:introduced=3.3.0,fixed=3.4.5, GIT:introduced=0,fixed=61d313150b5f620d0b800896c4f2199005e84b1f,fixed=6d50ee9169acf813257c37b75babe9c28e83542a|ECOSYSTEM:introduced=3.3.0,fixed=3.4.5

Identifiers

  • CVE-2021-21241
  • GHSA-hh7m-rx4f-4vpv
  • PYSEC-2021-91

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