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FKIE_CVE-2020-26276

Vulnerability from fkie_nvd - Published: 2020-12-17 20:15 - Updated: 2026-06-17 03:07
Severity
10.0 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
Fleet is an open source osquery manager. In Fleet before version 3.5.1, due to issues in Go's standard library XML parsing, a valid SAML response may be mutated by an attacker to modify the trusted document. This can result in allowing unverified logins from a SAML IdP. Users that configure Fleet with SSO login may be vulnerable to this issue. This issue is patched in 3.5.1. The fix was made using https://github.com/mattermost/xml-roundtrip-validator If upgrade to 3.5.1 is not possible, users should disable SSO authentication in Fleet.
References
security-advisories@github.comhttps://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020Release Notes, Third Party Advisory
security-advisories@github.comhttps://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607Patch, Third Party Advisory
security-advisories@github.comhttps://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcxThird Party Advisory
security-advisories@github.comhttps://github.com/mattermost/xml-roundtrip-validatorThird Party Advisory
security-advisories@github.comhttps://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilitiesNot Applicable, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020Release Notes, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcxThird Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/mattermost/xml-roundtrip-validatorThird Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilitiesNot Applicable, Third Party Advisory
Impacted products
Vendor Product Version
fleetdm fleet *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "fleet",
          "vendor": "fleetdm",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.5.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "73A23340-9D58-472D-9ADD-4313F6B9C332",
              "versionEndExcluding": "3.5.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Fleet is an open source osquery manager. In Fleet before version 3.5.1, due to issues in Go\u0027s standard library XML parsing, a valid SAML response may be mutated by an attacker to modify the trusted document. This can result in allowing unverified logins from a SAML IdP. Users that configure Fleet with SSO login may be vulnerable to this issue. This issue is patched in 3.5.1. The fix was made using https://github.com/mattermost/xml-roundtrip-validator If upgrade to 3.5.1 is not possible, users should disable SSO authentication in Fleet."
    },
    {
      "lang": "es",
      "value": "Fleet es un administrador de osquery de c\u00f3digo abierto.\u0026#xa0;En Fleet versiones anteriores a 3.5.1, debido a problemas en el an\u00e1lisis de XML de la biblioteca est\u00e1ndar de Go, una respuesta v\u00e1lida SAML puede ser mutada por un atacante para modificar el documento confiable.\u0026#xa0;Esto puede resultar en permitir inicios de sesi\u00f3n no verificados desde un IdP SAML.\u0026#xa0;Los usuarios que configuran Fleet con inicio de sesi\u00f3n SSO pueden ser vulnerables a este problema.\u0026#xa0;Este problema est\u00e1 parcheado en la versi\u00f3n 3.5.1.\u0026#xa0;La correcci\u00f3n fue realizada usando https://github.com/mattermost/xml-roundtrip-validator si la actualizaci\u00f3n a la versi\u00f3n 3.5.1 no es posible, los usuarios deben deshabilitar la autenticaci\u00f3n SSO en Fleet"
    }
  ],
  "id": "CVE-2020-26276",
  "lastModified": "2026-06-17T03:07:58.797",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "MEDIUM",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 6.8,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 8.6,
        "impactScore": 6.4,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 10.0,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 6.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2020-12-17T20:15:13.760",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "url": "https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/mattermost/xml-roundtrip-validator"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Not Applicable",
        "Third Party Advisory"
      ],
      "url": "https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Release Notes",
        "Third Party Advisory"
      ],
      "url": "https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/mattermost/xml-roundtrip-validator"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Not Applicable",
        "Third Party Advisory"
      ],
      "url": "https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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