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CVE-2020-11743

Status: ModifiedMedium (5.5)—

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

Fedoraproject — FedoraXEN — XEN

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2020-11743",
  "cveTags": [],
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          "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
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          "confidentialityImpact": "NONE"
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        "acInsufInfo": false,
        "impactScore": 2.9,
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        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.9,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
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          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
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  "published": "2020-04-14T13:15:12.970",
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          "value": "CWE-755"
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      "value": "An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain."
    },
    {
      "lang": "es",
      "value": "Se detectó un problema en Xen versiones hasta 4.13.x, permitiendo a usuarios invitados del Sistema Operativo causar una denegación de servicio debido a una ruta de error incorrecta en GNTTABOP_map_grant. Es esperado que las operaciones de la tabla de concesiones devuelvan 0 para el éxito y un número negativo para los errores. Algunos corchetes mal colocados causan que una ruta de error devuelva 1 en lugar de un valor negativo. El código de la tabla de concesión en Linux trata esta condición como exitosa y continúa incorrectamente con un estado inicializado. Un invitado con errores o malicioso puede construir su tabla de concesión de tal manera que, cuando un dominio del backend intente asignar una concesión, llegue a la ruta de error incorrecta. Esto bloqueará un dom0 o un dominio del backend basado en Linux."
    }
  ],
  "lastModified": "2026-06-17T02:50:43.603",
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}