CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
Percentile
38.3%
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
Fixed by: https://github.com/davedoesdev/python-jwt/commit/88ad9e67c53aa5f7c43ec4aa52ed34b7930068c9
None
Found by Tom Tervoort
https://github.com/pypa/advisory-database/blob/main/vulns/python-jwt/PYSEC-2022-259.yaml
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 to python-jwt.
If you have any questions or comments about this advisory, please open an issue in python-jwt
github.com/davedoesdev/python-jwt
github.com/davedoesdev/python-jwt/commit/6c5075469847b9e8b6e5336077d989d77a4d2bf1
github.com/davedoesdev/python-jwt/commit/88ad9e67c53aa5f7c43ec4aa52ed34b7930068c9
github.com/davedoesdev/python-jwt/security/advisories/GHSA-5p8v-58qm-c7fp
github.com/pypa/advisory-database/blob/main/vulns/python-jwt/PYSEC-2022-259.yaml
nvd.nist.gov/vuln/detail/CVE-2022-39227