{
  "affected": [
    {
      "affectedData": [
        {
          "product": "security-advisories",
          "vendor": "nextcloud",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.4.2"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.0.0-beta.1, \u003c 2.4.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:nextcloud:two-factor_webauthn:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C71FF026-3DFA-48DF-BCEE-7A5434D0E0D1",
              "versionEndExcluding": "1.4.2",
              "versionStartIncluding": "1.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:two-factor_webauthn:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "35454E68-E1E9-4955-9E67-BA56A57E2BFC",
              "versionEndExcluding": "2.4.1",
              "versionStartIncluding": "2.0.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud. Prior to 1.4.2 and 2.4.1, a missing ownership check allowed an attack to take-away a 2FA webauthn device when correctly guessing a 80-128 character long random string of letters, numbers and symbols. The victim would then be prompted to register a new device on the next login. The attacker can not authenticate as the victim. This vulnerability is fixed in 1.4.2 and 2.4.1."
    },
    {
      "lang": "es",
      "value": "Nextcloud Twofactor WebAuthn es el WebAuthn Two?Factor Provider para Nextcloud. Versiones anteriores a 1.4.2 y 2.4.1, una falta de verificaci\u00f3n de propiedad permiti\u00f3 que un atacante tomara un dispositivo 2FA WebAuthn al adivinar correctamente una cadena aleatoria de 80?128 caracteres de letras, n\u00fameros y s\u00edmbolos. La v\u00edctima ser\u00eda entonces solicitada a registrar un nuevo dispositivo en el pr\u00f3ximo inicio de sesi\u00f3n. El atacante no puede autenticarse como la v\u00edctima. Esta vulnerabilidad est\u00e1 corregida en 1.4.2 y 2.4.1."
    }
  ],
  "id": "CVE-2025-66558",
  "lastModified": "2026-10-15T21:10:00.327",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.1,
          "baseSeverity": "LOW",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-66558",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-12-05T18:35:39.199259Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-12-05T18:15:59.140",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-fr8x-mvjg-wf9q"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/nextcloud/twofactor_webauthn/commit/5d2302166d31ee2e01b2e21556bd5372156da13d"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "url": "https://github.com/nextcloud/twofactor_webauthn/pull/881"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Permissions Required",
        "Vendor Advisory"
      ],
      "url": "https://hackerone.com/reports/3360354"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}