FKIE_CVE-2020-12820

Vulnerability from fkie_nvd - Published: 2024-12-19 11:15 - Updated: 2026-06-17 02:52
Severity
5.4 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
Under non-default configuration, a stack-based buffer overflow in FortiOS version 6.0.10 and below, version 5.6.12 and below may allow a remote attacker authenticated to the SSL VPN to crash the FortiClient NAC daemon (fcnacd) and potentially execute arbitrary code via requesting a large FortiClient file name. We are not aware of proof of concept code successfully achieving the latter.
References
psirt@fortinet.comhttps://fortiguard.fortinet.com/psirt/FG-IR-20-083Vendor Advisory
Impacted products
Vendor Product Version
fortinet fortios *
fortinet fortios *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "cpes": [
            "cpe:2.3:o:fortinet:fortios:6.0.10:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.9:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.8:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.7:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.6:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.5:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.4:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.3:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.2:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.1:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:6.0.0:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.12:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.11:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.10:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.9:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.8:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.7:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.6:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.5:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.4:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.3:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.2:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.1:*:*:*:*:*:*:*",
            "cpe:2.3:o:fortinet:fortios:5.6.0:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "product": "FortiOS",
          "vendor": "Fortinet",
          "versions": [
            {
              "lessThanOrEqual": "6.0.10",
              "status": "affected",
              "version": "6.0.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.6.12",
              "status": "affected",
              "version": "5.6.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "psirt@fortinet.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "8C8DACBF-C9D5-4898-8294-DB887A28A9C7",
              "versionEndExcluding": "5.6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D44B5E8F-6093-4E84-9197-4530032E5B5A",
              "versionEndExcluding": "6.0.11",
              "versionStartIncluding": "6.0.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Under non-default configuration, a stack-based buffer overflow in FortiOS version 6.0.10 and below, version 5.6.12 and below may allow a remote attacker authenticated to the SSL VPN to crash the FortiClient NAC daemon (fcnacd) and potentially execute arbitrary code via requesting a large FortiClient file name. We are not aware of proof of concept code successfully achieving the latter."
    },
    {
      "lang": "es",
      "value": "En una configuraci\u00f3n no predeterminada, un desbordamiento de b\u00fafer basado en pila en FortiOS versi\u00f3n 6.0.10 y anteriores, versi\u00f3n 5.6.12 y anteriores puede permitir que un atacante remoto autenticado en la VPN SSL bloquee el daemon NAC de FortiClient (fcnacd) y potencialmente ejecute c\u00f3digo arbitrario mediante la solicitud de un nombre de archivo FortiClient grande. No tenemos conocimiento de ning\u00fan c\u00f3digo de prueba de concepto que logre esto \u00faltimo con \u00e9xito."
    }
  ],
  "id": "CVE-2020-12820",
  "lastModified": "2026-06-17T02:52:22.410",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.4,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.5,
        "source": "psirt@fortinet.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2020-12820",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-12-20T17:24:49.607607Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2024-12-19T11:15:05.700",
  "references": [
    {
      "source": "psirt@fortinet.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://fortiguard.fortinet.com/psirt/FG-IR-20-083"
    }
  ],
  "sourceIdentifier": "psirt@fortinet.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-121"
        }
      ],
      "source": "psirt@fortinet.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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