CVE-2019-18423

{
  "id": "CVE-2019-18423",
  "cveTags": [],
  "metrics": {
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        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 8.5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:M/Au:S/C:C/I:C/A:C",
          "authentication": "SINGLE",
          "integrityImpact": "COMPLETE",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "COMPLETE",
          "confidentialityImpact": "COMPLETE"
        },
        "acInsufInfo": false,
        "impactScore": 10,
        "baseSeverity": "HIGH",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 6.8,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
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          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.8
      }
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  "affected": [
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      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2019-10-31T14:15:11.137",
  "references": [
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    },
    {
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    {
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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      "tags": [
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      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-193"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m->max_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m->max_mapped_gfn will be updated using the original frame. It would be possible to set p2m->max_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m->max_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected."
    },
    {
      "lang": "es",
      "value": "Se detectó un problema en Xen versiones hasta 4.12.x, permitiendo a usuarios del sistema operativo invitado de ARM causar una denegación de servicio por medio de una hipercall Xmapme_add_to_physmap. p2m-)max_mapped_gfn es utilizado por las funciones p2m_resolve_translation_fault() y p2m_get_entry() para comprobar trama física del invitado. El resto del código en las dos funciones asumirá que existe una tabla root válida y lo comprobará con BUG_ON(). La función p2m_get_root_pointer() ignorará los bits superiores no utilizados de una trama física de invitado. Esto significa que la función p2m_set_entry() renombrará la trama. Sin embargo, p2m-)max_mapped_gfn será actualizada utilizando la trama original. Sería posible establecer p2m-)max_mapped_gfn lo suficientemente alto como para cubrir una trama que conllevaría a p2m_get_root_pointer() a devolver NULL en p2m_get_entry() y p2m_resolve_translation_fault(). Adicionalmente, la comprobación de saneamiento en p2m-)max_mapped_gfn está por un paso permitiendo que el \"highest mapped + 1\" sea considerado válido. Sin embargo, p2m_get_root_pointer() devolverá NULL. El problema podría desencadenarse con una hipercall especialmente diseñada XENMEM_add_to_physmap{, _batch} seguido de un acceso a una dirección (por medio de hipercall o acceso directo) que pasa la comprobación de saneamiento pero hace que la función p2m_get_root_pointer() devuelva NULL. Un administrador invitado malicioso puede causar un bloqueo del hipervisor, resultando en una Denegación de Servicio (DoS). Xen versión 4.8 y mas recientes son vulnerables. Solo los sistemas Arm son vulnerables. Los sistemas x86 no están afectados."
    }
  ],
  "lastModified": "2026-06-17T02:25:00.687",
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}