« Volver al listado

CVE-2020-12812

Estado: AnalizadaCrítica (9.8)⚠ Explotación activa

An improper authentication vulnerability in SSL VPN in FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below may result in a user being able to log in successfully without being prompted for the second factor of authentication (FortiToken) if they changed the case of their username.

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).

CISA KEV — explotada activamente

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad de autenticación en SSL VPN expuesto (AV:N, PR:N) que permite bypass de segundo factor modificando mayúsculas. Habilita acceso no autorizado (T1078) y potencial ejecución remota en contexto autenticado (ransomware confirmado).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account ManagementApplication Developer GuidanceActive Directory ConfigurationVulnerability ScanningUser TrainingUser Account Management

Tecnologías afectadas (1)

Fortinet — Fortios

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2020-12812",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2020-12812",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "active"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-08-12T03:55:19.062068Z"
        }
      }
    ],
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 7.5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "HIGH",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "psirt@fortinet.com",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "Fortinet FortiOS",
          "versions": [
            {
              "status": "affected",
              "version": "FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below"
            }
          ]
        }
      ]
    }
  ],
  "published": "2020-07-24T23:15:12.003",
  "references": [
    {
      "url": "https://fortiguard.com/psirt/FG-IR-19-283",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "psirt@fortinet.com"
    },
    {
      "url": "https://fortiguard.com/psirt/FG-IR-19-283",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-12812",
      "tags": [
        "US Government Resource"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-178"
        },
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An improper authentication vulnerability in SSL VPN in FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below may result in a user being able to log in successfully without being prompted for the second factor of authentication (FortiToken) if they changed the case of their username."
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad de autenticación inapropiada en SSL VPN en FortiOS versiones 6.4.0, 6.2.0 a 6.2.3, 6.0.9 y posteriores, puede resultar en que un usuario sea capaz de iniciar sesión con éxito sin que sea requerido el segundo factor de autenticación (FortiToken) si cambiaron el caso de su nombre de usuario"
    }
  ],
  "lastModified": "2026-10-02T14:54:53.040",
  "cisaActionDue": "2022-05-03",
  "cisaExploitAdd": "2021-11-03",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "756167D1-ED53-4EC7-88B3-D82E329A2FA4",
              "versionEndExcluding": "6.0.10"
            },
            {
              "criteria": "cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "BD0966DA-A4B1-4C78-862C-3CB9557DCC4C",
              "versionEndExcluding": "6.2.4",
              "versionStartIncluding": "6.2.0"
            },
            {
              "criteria": "cpe:2.3:o:fortinet:fortios:6.4.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "1C6E45EB-4C8C-4777-9200-08B14595A3A7"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "psirt@fortinet.com",
  "cisaRequiredAction": "Apply updates per vendor instructions.",
  "cisaVulnerabilityName": "Fortinet FortiOS SSL VPN Improper Authentication Vulnerability"
}