« Volver al listado

CVE-2021-4095

Estado: ModificadaMedia (5.5)—

Se encontró una desreferencia de puntero NULL en el KVM del kernel de Linux cuando se habilita el registro de anillo sucio sin un contexto de vCPU activo. Un atacante local no privilegiado en el host puede usar este fallo para causar una condición de oops del kernel y, por tanto, una denegación de servicio emitiendo un ioctl KVM_XEN_HVM_SET_ATTR. Este fallo afecta a el kernel de Linux versiones anteriores a 5.17-rc1

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 (2)

Fedoraproject — FedoraLinux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2021-4095",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 1.9,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:M/Au:N/C:N/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "LOW",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.4,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "kernel",
          "versions": [
            {
              "status": "affected",
              "version": "Linux kernel versions prior to 5.17-rc1"
            }
          ]
        }
      ]
    }
  ],
  "published": "2022-03-10T17:44:53.563",
  "references": [
    {
      "url": "http://www.openwall.com/lists/oss-security/2022/01/17/1",
      "tags": [
        "Exploit",
        "Mailing List",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2031194",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QIOQN7JJNN6ABIDGRSTVZA65MHRLMH2Q/",
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VT6573CGKVK3DU2632VVO5BVM4IU7SBV/",
      "source": "secalert@redhat.com"
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2022/01/17/1",
      "tags": [
        "Exploit",
        "Mailing List",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2031194",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QIOQN7JJNN6ABIDGRSTVZA65MHRLMH2Q/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VT6573CGKVK3DU2632VVO5BVM4IU7SBV/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secalert@redhat.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A NULL pointer dereference was found in the Linux kernel's KVM when dirty ring logging is enabled without an active vCPU context. An unprivileged local attacker on the host may use this flaw to cause a kernel oops condition and thus a denial of service by issuing a KVM_XEN_HVM_SET_ATTR ioctl. This flaw affects Linux kernel versions prior to 5.17-rc1."
    },
    {
      "lang": "es",
      "value": "Se encontró una desreferencia de puntero NULL en el KVM del kernel de Linux cuando se habilita el registro de anillo sucio sin un contexto de vCPU activo. Un atacante local no privilegiado en el host puede usar este fallo para causar una condición de oops del kernel y, por tanto, una denegación de servicio emitiendo un ioctl KVM_XEN_HVM_SET_ATTR. Este fallo afecta a el kernel de Linux versiones anteriores a 5.17-rc1"
    }
  ],
  "lastModified": "2026-06-17T04:19:01.513",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "192D8BB7-2231-48C2-8534-05844F7BF470",
              "versionEndIncluding": "5.16"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A930E247-0B43-43CB-98FF-6CE7B8189835"
            },
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "80E516C0-98A4-4ADE-B69F-66A772E2BAAA"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}