Search criteria ⓘ Use this form to refine search results.
Full-text search supports keyword queries with ranking and filtering.
You can combine vendor, product, and sources to narrow results.
Enable “Apply ordering” to sort by date instead of relevance.

1 vulnerability by joaquimserafim

CVE-2023-48238 (GCVE-0-2023-48238)

Vulnerability from cvelistv5 – Published: 2023-11-17 21:35 – Updated: 2026-06-08 23:38
VLAI
Title
JWT Algorithm Confusion in json-web-token library
Summary
joaquimserafim/json-web-token is a javascript library use to interact with JSON Web Tokens (JWT) which are a compact URL-safe means of representing claims to be transferred between two parties. Versions prior to 4.0.0 are vulnerable to a JWT algorithm confusion attack. On line 86 of the 'index.js' file, the algorithm to use for verifying the signature of the JWT token is taken from the JWT token, which at that point is still unverified and thus shouldn't be trusted. To exploit this vulnerability, an attacker needs to craft a malicious JWT token containing the HS256 algorithm, signed with the public RSA key of the victim application. This attack will only work against this library is the RS256 algorithm is in use, however it is a best practice to use that algorithm. Version 4.0.0 fixes the issue.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-345 - Insufficient Verification of Data Authenticity
Assigner
References
Impacted products
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-02T21:23:39.429Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "name": "https://github.com/joaquimserafim/json-web-token/security/advisories/GHSA-4xw9-cx39-r355",
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/joaquimserafim/json-web-token/security/advisories/GHSA-4xw9-cx39-r355"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2023-48238",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-10-11T15:24:35.730245Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-10-11T15:24:50.982Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "json-web-token",
          "vendor": "joaquimserafim",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 4.0.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "joaquimserafim/json-web-token is a javascript library use to interact with JSON Web Tokens (JWT) which are a compact URL-safe means of representing claims to be transferred between two parties. Versions prior to 4.0.0 are vulnerable to a JWT algorithm confusion attack. On line 86 of the \u0027index.js\u0027 file, the algorithm to use for verifying the signature of the JWT token is taken from the JWT token, which at that point is still unverified and thus shouldn\u0027t be trusted. To exploit this vulnerability, an attacker needs to craft a malicious JWT token containing the HS256 algorithm, signed with the public RSA key of the victim application. This attack will only work against this library is the RS256 algorithm is in use, however it is a best practice to use that algorithm. Version 4.0.0 fixes the issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-345",
              "description": "CWE-345: Insufficient Verification of Data Authenticity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-08T23:38:16.955Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/joaquimserafim/json-web-token/security/advisories/GHSA-4xw9-cx39-r355",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/joaquimserafim/json-web-token/security/advisories/GHSA-4xw9-cx39-r355"
        },
        {
          "name": "https://github.com/joaquimserafim/json-web-token/commit/b6e56b1346f48432d29133c76b65222ad93956b7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/joaquimserafim/json-web-token/commit/b6e56b1346f48432d29133c76b65222ad93956b7"
        }
      ],
      "source": {
        "advisory": "GHSA-4xw9-cx39-r355",
        "discovery": "UNKNOWN"
      },
      "title": "JWT Algorithm Confusion in json-web-token library"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2023-48238",
    "datePublished": "2023-11-17T21:35:00.111Z",
    "dateReserved": "2023-11-13T13:25:18.482Z",
    "dateUpdated": "2026-06-08T23:38:16.955Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}