Описание
Potential Captcha Validate Bypass in flask-session-captcha
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:
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.
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
Ссылки
- https://github.com/Tethik/flask-session-captcha/security/advisories/GHSA-7r87-cj48-wj45
- https://nvd.nist.gov/vuln/detail/CVE-2022-24880
- https://github.com/Tethik/flask-session-captcha/pull/27
- https://github.com/Tethik/flask-session-captcha/commit/2811ae23a38d33b620fb7a07de8837c6d65c13e4
- https://github.com/Tethik/flask-session-captcha/releases/tag/v1.2.1
- https://github.com/pypa/advisory-database/tree/main/vulns/flask-session-captcha/PYSEC-2022-193.yaml
Пакеты
flask-session-captcha
< 1.2.1
1.2.1
EPSS
6.9 Medium
CVSS4
5.3 Medium
CVSS3
CVE ID
Дефекты
Связанные уязвимости
flask-session-captcha is a package which allows users to extend Flask by adding an image based captcha stored in a server side session. In versions prior to 1.2.1, he `captcha.validate()` function would return `None` if passed no value (e.g. by submitting an having an empty form). If implementing users were checking the return value to be **False**, the captcha verification check could be bypassed. Version 1.2.1 fixes the issue. Users can workaround the issue by not explicitly checking that the value is False. Checking the return value less explicitly should still work.
EPSS
6.9 Medium
CVSS4
5.3 Medium
CVSS3