CVE-2017-11424: Pyjwt PyJWT Vulnerable To Key Confusion Vulnerability

HIGH
Advisory Identifier: GHSA-r9jw-mwhq-wp62
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CVSS 7.5
Published
Advisory Summary

CVE-2017-11424 is a HIGH (CVSS 7.5) pyjwt vulnerable to key confusion vulnerability (General Security Weakness) affecting Pyjwt libraries in the PyPI ecosystem. The issue involves pyjwt vulnerable to key confusion attacks. Remediation is available by upgrading affected packages to version 1.5.1.

CVE-2017-11424 at a Glance

CVE Identifier CVE-2017-11424
GHSA Identifier GHSA-r9jw-mwhq-wp62
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification General Security Weakness
Affected Product Pyjwt
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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 None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2017-11424

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

pyjwt fixed: 1.5.1 
pip install pyjwt>=1.5.1
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 pyjwt

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2017-11424, inspect your installed packages using pip:

pip show pyjwt

Analyze the terminal output to locate any version of Pyjwt in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.5.1), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Pyjwt, 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

In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.

CVE-2017-11424 Affected Pyjwt Versions

1 component(s)
Fixed Versions:
1.5.1
Product / Package Ecosystem Affected Versions Fixed Version
pyjwt
pypi/pyjwt
PyPI
< 1.5.1
1.5.1

References

NVD — CVE-2017-11424 NVD
https://nvd.nist.gov/vuln/detail/CVE-2017-11424
Pyjwt Source Repository REPOSITORY
https://github.com/jpadilla/pyjwt/pull/277
Pyjwt Source Repository REPOSITORY
https://github.com/jpadilla/pyjwt
Pyjwt Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/pyjwt/PYSEC-2017-24.yaml
Pyjwt Security Information SECURITY
http://www.debian.org/security/2017/dsa-3979

Frequently Asked Questions

What is CVE-2017-11424?
CVE-2017-11424 is a security vulnerability in Pyjwt involving PyJWT vulnerable to key confusion attacks under General Security Weakness.
Which Pyjwt versions are affected?
Affected versions include releases prior to 1.5.1 across affected packages: pyjwt.
What version fixes CVE-2017-11424?
Upgrading to 1.5.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pyjwt affected?
Yes, pyjwt is affected in releases prior to 1.5.1. Upgrade your dependency to 1.5.1 or later.
What is the CVSS score of CVE-2017-11424?
CVE-2017-11424 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2017-11424?
CVE-2017-11424 is classified under General Security Weakness.
How can I check PyPI dependencies for CVE-2017-11424?
Run the dependency tree command: 'pip show pyjwt'. 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-r9jw-mwhq-wp62",
  "modified" : "2024-10-15T16:34:39Z",
  "published" : "2022-05-13T01:42:19Z",
  "aliases" : [ "CVE-2017-11424" ],
  "summary" : "PyJWT vulnerable to key confusion attacks",
  "details" : "In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pyjwt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.5.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2017-11424"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jpadilla/pyjwt/pull/277"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jpadilla/pyjwt"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/pyjwt/PYSEC-2017-24.yaml"
  }, {
    "type" : "WEB",
    "url" : "http://www.debian.org/security/2017/dsa-3979"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-09-12T14:50:37Z",
    "nvd_published_at" : "2017-08-24T16:29:00Z"
  }
}