FKIE_CVE-2020-14000

Vulnerability from fkie_nvd - Published: 2020-07-16 15:15 - Updated: 2026-06-17 02:54
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
MIT Lifelong Kindergarten Scratch scratch-vm before 0.2.0-prerelease.20200714185213 loads extension URLs from untrusted project.json files with certain _ characters, resulting in remote code execution because the URL's content is treated as a script and is executed as a worker. The responsible code is getExtensionIdForOpcode in serialization/sb3.js. The use of _ is incompatible with a protection mechanism in older versions, in which URLs were split and consequently deserialization attacks were prevented. NOTE: the scratch.mit.edu hosted service is not affected because of the lack of worker scripts.
References
cve@mitre.orghttps://github.com/LLK/scratch-vm/pull/2476Third Party Advisory
cve@mitre.orghttps://scratch.mit.edu/discuss/topic/422904/?page=1#post-4223443Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/LLK/scratch-vm/pull/2476Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://scratch.mit.edu/discuss/topic/422904/?page=1#post-4223443Vendor Advisory
Impacted products
Vendor Product Version
mit scratch-vm *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "source": "cve@mitre.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mit:scratch-vm:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5136B7DB-86C0-44B3-B2F4-64004F59C190",
              "versionEndExcluding": "0.2.0-prerelease.20200714185213",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MIT Lifelong Kindergarten Scratch scratch-vm before 0.2.0-prerelease.20200714185213 loads extension URLs from untrusted project.json files with certain _ characters, resulting in remote code execution because the URL\u0027s content is treated as a script and is executed as a worker. The responsible code is getExtensionIdForOpcode in serialization/sb3.js. The use of _ is incompatible with a protection mechanism in older versions, in which URLs were split and consequently deserialization attacks were prevented. NOTE: the scratch.mit.edu hosted service is not affected because of the lack of worker scripts."
    },
    {
      "lang": "es",
      "value": "MIT Lifelong Kindergarten Scratch scratch-vm versiones anteriores a 0.2.0-prerelease.20200714185213, carga una URL de extensi\u00f3n de archivos project.json no confiables con determinados caracteres _, resultando en una ejecuci\u00f3n de c\u00f3digo remota porque el contenido de la URL es tratado como un script y es ejecutado como un trabajador. El c\u00f3digo responsable es getExtensionIdForOpcode en serialization/sb3.js. El uso de _ es incompatible con un mecanismo de protecci\u00f3n en versiones anteriores, en las que las URL fueron divididas y, en consecuencia, los ataques de deserializaci\u00f3n fueron impedidos. NOTA: el servicio alojado scratch.mit.eduno est\u00e1 afectado por la falta de scripts de trabajo"
    }
  ],
  "id": "CVE-2020-14000",
  "lastModified": "2026-06-17T02:54:04.837",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 7.5,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 6.4,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2020-07-16T15:15:27.860",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/LLK/scratch-vm/pull/2476"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://scratch.mit.edu/discuss/topic/422904/?page=1#post-4223443"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/LLK/scratch-vm/pull/2476"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://scratch.mit.edu/discuss/topic/422904/?page=1#post-4223443"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-502"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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