CVE-2022-39227

python-jwt is a module for generating and verifying JSON Web Tokens. Versions prior to 3.3.4 are subject to Authentication Bypass by Spoofing, resulting in identity spoofing, session hijacking or authentication bypass. An attacker who obtains a JWT can arbitrarily forge its contents without knowing the secret key. Depending on the application, this may for example enable the attacker to spoof other user's identities, hijack their sessions, or bypass authentication. Users should upgrade to version 3.3.4. There are no known workarounds.

python-jwt is a module for generating and verifying JSON Web Tokens. Versions prior to 3.3.4 are subject to Authentication Bypass by Spoofing, resulting in identity spoofing, session hijacking or authentication bypass. An attacker who obtains a JWT can arbitrarily forge its contents without knowing the secret key. Depending on the application, this may for example enable the attacker to spoof other user's identities, hijack their sessions, or bypass authentication. Users should upgrade to version 3.3.4. There are no known workarounds.

An attacker who obtains a JWT can arbitrarily forge its contents without knowing the secret key. Depending on the application, this may for example enable the attacker to spoof other user's identities, hijack their sessions, or bypass authentication.

### Impact An attacker who obtains a JWT can arbitrarily forge its contents without knowing the secret key. Depending on the application, this may for example enable the attacker to spoof other user's identities, hijack their sessions, or bypass authentication. ### Patches Users should upgrade to version 3.3.4 Fixed by: https://github.com/davedoesdev/python-jwt/commit/88ad9e67c53aa5f7c43ec4aa52ed34b7930068c9 ### Workarounds None ### References Found by [Tom Tervoort](Tom.Tervoort@secura.com) https://github.com/pypa/advisory-database/blob/main/vulns/python-jwt/PYSEC-2022-259.yaml ### More information The vulnerability allows an attacker, who possesses a single valid JWT, to create a new token with forged claims that the verify_jwt function will accept as valid. The issue is caused by an inconsistency between the JWT parsers used by python-jwt and its dependency jwcrypto. By mixing compact and JSON representations, an attacker can trick jwcrypto of parsing different claims than those over which a signature is validated by jwcrypto. Testing the fix has been added as an [automated unit test](https://github.com/davedoesdev/python-jwt/blob/master/test/vulnerability_vows.py) to python-jwt. If you have any questions or comments about this advisory, please open an issue in [python-jwt](https://github.com/davedoesdev/python-jwt)

python-jwt es un módulo para generar y verificar tokens web JSON. Las versiones anteriores a 3.3.4, están sujetas a Una Omisión de la Autenticación por medio de Suplantación, resultando en una suplantación de identidad, secuestro de la sesión o omisión de autenticación. Un atacante que obtiene un JWT puede falsificar arbitrariamente su contenido sin conocer la clave secreta. Dependiendo de la aplicación, esto puede permitir al atacante, por ejemplo, falsificar la identidad de otros usuarios, secuestrar sus sesiones o omitir la autenticación. Los usuarios deben actualizar a versión 3.3.4. No se presentan mitigaciones conocidas.