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CVE-2019-14842

Estado: ModificadaCrítica (9.8)—

Structured reply is a feature of the newstyle NBD protocol allowing the server to send a reply in chunks. A bounds check which was supposed to test for chunk offsets smaller than the beginning of the request did not work because of signed/unsigned confusion. If one of these chunks contains a negative offset then data under control of the server is written to memory before the read buffer supplied by the client. If the read buffer is located on the stack then this allows the stack return address from nbd_pread() to be trivially modified, allowing arbitrary code execution under the control of the server. If the buffer is located on the heap then other memory objects before the buffer can be overwritten, which again would usually lead to arbitrary code execution.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Redhat — Libnbd

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2019-14842",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 7.5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "HIGH",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
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    "cvssMetricV30": [
      {
        "type": "Secondary",
        "source": "secalert@redhat.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.0",
          "baseScore": 7.3,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "LOW",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 3.4,
        "exploitabilityScore": 3.9
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
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        "cvssData": {
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          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
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          "confidentialityImpact": "HIGH"
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  "affected": [
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      "affectedData": [
        {
          "vendor": "[UNKNOWN]",
          "product": "libnbd",
          "versions": [
            {
              "status": "affected",
              "version": "1.0.3"
            }
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        }
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    }
  ],
  "published": "2019-11-26T16:15:11.963",
  "references": [
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14842",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://www.redhat.com/archives/libguestfs/2019-October/msg00060.html",
      "tags": [
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        "Third Party Advisory"
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        "Third Party Advisory"
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secalert@redhat.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-681"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-681"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Structured reply is a feature of the newstyle NBD protocol allowing the server to send a reply in chunks. A bounds check which was supposed to test for chunk offsets smaller than the beginning of the request did not work because of signed/unsigned confusion. If one of these chunks contains a negative offset then data under control of the server is written to memory before the read buffer supplied by the client. If the read buffer is located on the stack then this allows the stack return address from nbd_pread() to be trivially modified, allowing arbitrary code execution under the control of the server. If the buffer is located on the heap then other memory objects before the buffer can be overwritten, which again would usually lead to arbitrary code execution."
    },
    {
      "lang": "es",
      "value": "Una respuesta estructurada es una funcionalidad del nuevo protocolo NBD que permite al servidor enviar una respuesta en fragmentos. Una comprobación de límites que se suponía que probaría las compensaciones de fragmentos más pequeñas que al comienzo de la petición no funcionó debido a la confusión de signed/unsigned. Si uno de estos fragmentos contiene un desplazamiento negativo, los datos bajo control del servidor son escritos en la memoria antes del búfer de lectura suministrado por el cliente. Si el búfer de lectura es localizado en la pila, esto permite modificar trivialmente la dirección de retorno de la pila desde la función nbd_pread(), permitiendo la ejecución de código arbitrario bajo el control del servidor. Si el búfer se encuentra en la pila, entonces otros objetos de memoria antes de que el búfer pueda ser sobrescrito, lo que de nuevo conllevaría usualmente a la ejecución de código arbitrario."
    }
  ],
  "lastModified": "2026-06-17T02:19:08.973",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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              "vulnerable": true,
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              "versionEndExcluding": "1.0.3"
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  "sourceIdentifier": "secalert@redhat.com"
}