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GHSA-7r87-cj48-wj45

Опубликовано: 26 апр. 2022
Источник: github
Github: Прошло ревью
CVSS4: 6.9
CVSS3: 5.3

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:

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:

Пакеты

Наименование

flask-session-captcha

pip
Затронутые версииВерсия исправления

< 1.2.1

1.2.1

EPSS

Процентиль: 48%
0.0025
Низкий

6.9 Medium

CVSS4

5.3 Medium

CVSS3

Дефекты

CWE-253
CWE-394
CWE-754

Связанные уязвимости

CVSS3: 5.3
nvd
почти 4 года назад

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

Процентиль: 48%
0.0025
Низкий

6.9 Medium

CVSS4

5.3 Medium

CVSS3

Дефекты

CWE-253
CWE-394
CWE-754