GHSA-7r87-cj48-wj45

Source

https://github.com/advisories/GHSA-7r87-cj48-wj45

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/04/GHSA-7r87-cj48-wj45/GHSA-7r87-cj48-wj45.json

JSON Data

https://api.test.osv.dev/v1/vulns/GHSA-7r87-cj48-wj45

Aliases

Related

CVE-2022-24880

Published

2022-04-26T21:19:52Z

Modified

2024-09-20T21:25:20.021255Z

Severity

5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator

Summary

Potential Captcha Validate Bypass in flask-session-captcha

Details

Impact

flask-session-captcha is a package which allows users to extend Flask by adding an image based captcha stored in a server side session.

The captcha.validate() function would return None if passed no value (e.g. by submitting a request with an empty form).

If implementing users were checking the return value to be False, the captcha verification check could be bypassed.

Sample vulnerable code:

if captcha.validate() == False:
    ... # abort
else:
   ... # do stuff

Patches

A new version (1.2.1) is available that fixes the issue.

Workarounds

Users can workaround the issue by not explicitly checking that the value is False.

Checking the return value less explicitly should still work.

if not captcha.validate():
    ... # abort
else:
   ... # do stuff

if captcha.validate():
    ... # do stuff
else:
   ... # abort

References

https://github.com/Tethik/flask-session-captcha/pull/27

For more information

If you have any questions or comments about this advisory: * Open an issue in the github repo

Database specific

{
    "nvd_published_at": "2022-04-25T22:15:00Z",
    "cwe_ids": [
        "CWE-253",
        "CWE-394",
        "CWE-754"
    ],
    "severity": "MODERATE",
    "github_reviewed": true,
    "github_reviewed_at": "2022-04-26T21:19:52Z"
}

References

Affected packages

PyPI / flask-session-captcha

Package

Name: flask-session-captcha; View open source insights on deps.dev
Purl: pkg:pypi/flask-session-captcha

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.2.1

Affected versions

1.*

1.0.0

1.0.1

1.0.2

1.0.3

1.1.0

1.2.0

Ecosystem specific

{
    "affected_functions": [
        "flask_session_captcha.FlaskSessionCaptcha.validate"
    ]
}