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BREW-AZURE-CLI-CVE-2017-11424 (GHSA-R9JW-MWHQ-WP62)

Vulnerability from osv_homebrew – Published: 2026-08-13 16:37 – Updated: 2026-09-09 23:43 – Source website
VLAI
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
7.5 (High)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "PyJWT",
        "resource_purl": "pkg:pypi/pyjwt@2.13.0",
        "upstream_fixed_in": "1.5.1"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "azure-cli",
        "purl": "pkg:brew/azure-cli"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.89.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/pyjwt@2.13.0",
        "name": "pyjwt",
        "resource": "PyJWT",
        "strategy": "registry",
        "subject_version": "2.13.0"
      }
    ]
  },
  "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.",
  "id": "BREW-azure-cli-CVE-2017-11424",
  "modified": "2026-09-09T23:43:05Z",
  "published": "2026-08-13T16:37:03Z",
  "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"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "PyJWT vulnerable to key confusion attacks",
  "upstream": [
    "GHSA-r9jw-mwhq-wp62",
    "CVE-2017-11424",
    "PYSEC-2017-24"
  ]
}



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