CVE-2022-39227: Python jwt Python-jwt Vulnerable To Token Forgery Vulnerability

CRITICAL
Advisory Identifier: GHSA-5p8v-58qm-c7fp
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CVSS 9.1
CWE-290
Published
Advisory Summary

CVE-2022-39227 is a CRITICAL (CVSS 9.1) python-jwt vulnerable to token forgery vulnerability (CWE-290: Authentication Bypass by Spoofing) affecting Python jwt libraries in the PyPI ecosystem. The issue involves python-jwt vulnerable to token forgery with new claims. Remediation is available by upgrading affected packages to version 3.3.4.

CVE-2022-39227 at a Glance

CVE Identifier CVE-2022-39227
GHSA Identifier GHSA-5p8v-58qm-c7fp
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-290: Authentication Bypass by Spoofing
Affected Product Python jwt
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2022-39227

To remediate this vulnerability, upgrade all affected Python jwt dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

python-jwt fixed: 3.3.4 
pip install python-jwt>=3.3.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show python-jwt

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2022-39227, inspect your installed packages using pip:

pip show python-jwt

Analyze the terminal output to locate any version of Python jwt in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.3.4), your application is affected.

Note: The pip show python-jwt command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-290: Authentication Bypass by Spoofing, where this attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks. In Python jwt, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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)

CVE-2022-39227 Affected Python jwt Versions

1 component(s)
Fixed Versions:
3.3.4
Product / Package Ecosystem Affected Versions Fixed Version
python-jwt
pypi/python-jwt
PyPI
< 3.3.4
3.3.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/davedoesdev/python-jwt/security/advisories/GHSA-5p8v-58qm-c7fp
NVD — CVE-2022-39227 NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-39227
Security Fix Commit FIX COMMIT
https://github.com/davedoesdev/python-jwt/commit/6c5075469847b9e8b6e5336077d989d77a4d2bf1
Security Fix Commit FIX COMMIT
https://github.com/davedoesdev/python-jwt/commit/88ad9e67c53aa5f7c43ec4aa52ed34b7930068c9
Python jwt Source Repository REPOSITORY
https://github.com/davedoesdev/python-jwt
Python jwt Source Repository REPOSITORY
https://github.com/pypa/advisory-database/blob/main/vulns/python-jwt/PYSEC-2022-259.yaml
www.vicarius.io/vsociety/posts/auth... WEB
https://www.vicarius.io/vsociety/posts/authentication-bypass-in-python-jwt

Frequently Asked Questions

What is CVE-2022-39227?
CVE-2022-39227 is a security vulnerability in Python jwt involving python-jwt vulnerable to token forgery with new claims under CWE-290: Authentication Bypass by Spoofing.
Which Python jwt versions are affected?
Affected versions include releases prior to 3.3.4 across affected packages: python-jwt.
What version fixes CVE-2022-39227?
Upgrading to 3.3.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is python-jwt affected?
Yes, python-jwt is affected in releases prior to 3.3.4. Upgrade your dependency to 3.3.4 or later.
What is the CVSS score of CVE-2022-39227?
CVE-2022-39227 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2022-39227?
CVE-2022-39227 is classified under CWE-290: Authentication Bypass by Spoofing (This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.).
How can I check PyPI dependencies for CVE-2022-39227?
Run the dependency tree command: 'pip show python-jwt'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5p8v-58qm-c7fp",
  "modified" : "2024-07-10T21:32:14Z",
  "published" : "2022-09-21T21:33:22Z",
  "aliases" : [ "CVE-2022-39227" ],
  "summary" : "python-jwt vulnerable to token forgery with new claims",
  "details" : "### Impact\nAn 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.\n\n### Patches\nUsers should upgrade to version 3.3.4\nFixed by: https://github.com/davedoesdev/python-jwt/commit/88ad9e67c53aa5f7c43ec4aa52ed34b7930068c9\n\n### Workarounds\nNone\n\n### References\nFound by [Tom Tervoort](Tom.Tervoort@secura.com)\nhttps://github.com/pypa/advisory-database/blob/main/vulns/python-jwt/PYSEC-2022-259.yaml\n\n### More information\n\nThe 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.\n\nThe 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.\n\nTesting 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.\n\nIf you have any questions or comments about this advisory, please open an issue in [python-jwt](https://github.com/davedoesdev/python-jwt)\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
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    "ranges" : [ {
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  "references" : [ {
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  }, {
    "type" : "WEB",
    "url" : "https://github.com/davedoesdev/python-jwt/commit/6c5075469847b9e8b6e5336077d989d77a4d2bf1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/davedoesdev/python-jwt/commit/88ad9e67c53aa5f7c43ec4aa52ed34b7930068c9"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/davedoesdev/python-jwt"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/blob/main/vulns/python-jwt/PYSEC-2022-259.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://www.vicarius.io/vsociety/posts/authentication-bypass-in-python-jwt"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-290" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-09-21T21:33:22Z",
    "nvd_published_at" : "2022-09-23T07:15:00Z"
  }
}