« Volver al listado

CVE-2021-27862

Estado: ModificadaMedia (4.7)—

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion (and optionally VLAN0 headers).

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)

Ieee — Ieee 802.2Ietf — P802.1q

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2021-27862",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-27862",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-05-21T15:04:33.466068Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 4.7,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 2.8
      },
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 4.7,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "cret@cert.org",
      "affectedData": [
        {
          "vendor": "IEEE",
          "product": "802.2",
          "versions": [
            {
              "status": "affected",
              "version": "802.2h-1997",
              "versionType": "custom",
              "lessThanOrEqual": "802.2h-1997"
            }
          ]
        },
        {
          "vendor": "IETF",
          "product": "draft-ietf-v6ops-ra-guard-08",
          "versions": [
            {
              "status": "affected",
              "version": "08",
              "versionType": "custom",
              "lessThanOrEqual": "08"
            }
          ]
        }
      ]
    }
  ],
  "published": "2022-09-27T19:15:09.403",
  "references": [
    {
      "url": "https://blog.champtar.fr/VLAN0_LLC_SNAP/",
      "source": "cret@cert.org"
    },
    {
      "url": "https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "https://kb.cert.org/vuls/id/855201",
      "source": "cret@cert.org"
    },
    {
      "url": "https://standards.ieee.org/ieee/802.2/1048/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "https://blog.champtar.fr/VLAN0_LLC_SNAP/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://kb.cert.org/vuls/id/855201",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://standards.ieee.org/ieee/802.2/1048/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.kb.cert.org/vuls/id/855201",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "cret@cert.org",
      "description": [
        {
          "lang": "en",
          "value": "CWE-130"
        },
        {
          "lang": "en",
          "value": "CWE-290"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion (and optionally VLAN0 headers)."
    },
    {
      "lang": "es",
      "value": "Las capacidades de filtrado de red de capa 2, como la protección RA de IPv6, pueden omitirse usando encabezados LLC/SNAP con una longitud no válida y la conversión de tramas de Ethernet a Wifi (y, opcionalmente, encabezados VLAN0)"
    }
  ],
  "lastModified": "2026-06-17T03:45:32.623",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:ieee:ieee_802.2:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D5B0DDC2-21C5-4682-9AA2-055BF7C722DA",
              "versionEndIncluding": "802.2h-1997"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:ietf:p802.1q:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "94105D2E-950F-4290-8840-301FA908BC8C",
              "versionEndIncluding": "d1.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cret@cert.org"
}