« Volver al listado

CVE-2020-25601

Estado: ModificadaMedia (5.5)—

An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.

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 (4)

Debian — Debian LinuxFedoraproject — FedoraOpensuse — LeapXEN — XEN

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2020-25601",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 4.9,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:C",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "COMPLETE",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 6.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.9,
        "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": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2020-09-23T22:15:13.713",
  "references": [
    {
      "url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://security.gentoo.org/glsa/202011-06",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://www.debian.org/security/2020/dsa-4769",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://xenbits.xen.org/xsa/advisory-344.html",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://security.gentoo.org/glsa/202011-06",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.debian.org/security/2020/dsa-4769",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://xenbits.xen.org/xsa/advisory-344.html",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics."
    },
    {
      "lang": "es",
      "value": "Se detectó un problema en Xen versiones hasta 4.14.x. Se presenta una carencia de preferencia en evtchn_reset() / evtchn_destroy(). En particular, el modelo de canal de eventos FIFO permite a los invitados tener una gran cantidad de canales de eventos activos simultáneos. Cerrar todos estos (al restablecer todos los canales de eventos o al limpiar después del invitado) puede llevar períodos de tiempo prolongados. Hasta ahora, no había ningún arreglo para la preferencia a intervalos adecuados, lo que permitía que una CPU pasara una cantidad de tiempo casi ilimitada en el procesamiento de estas operaciones. Los kernels invitados maliciosos o con errores pueden montar un ataque de denegación de servicio (DoS) afectando a todo el sistema. Todas las versiones de Xen son vulnerables en principio. Tanto las versiones 4.3 y como las anteriores son vulnerables dependiendo de las características subyacentes del hardware."
    }
  ],
  "lastModified": "2026-06-17T03:06:57.593",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2D769F4A-98C6-4544-AC04-3D8600C17BBB",
              "versionEndIncluding": "4.14.0"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "80F0FA5D-8D3B-4C0E-81E2-87998286AF33"
            },
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "36D96259-24BD-44E2-96D9-78CE1D41F956"
            },
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E460AA51-FCDA-46B9-AE97-E6676AA5E194"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B009C22E-30A4-4288-BCF6-C3E81DEAF45A"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}