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CVE-2021-22877

Status: ModifiedMedium (6.5)—

A missing user check in Nextcloud prior to 20.0.6 inadvertently populates a user's own credentials for other users external storage configuration when not already configured yet.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

Fedoraproject — FedoraNextcloud — Nextcloud Server

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2021-22877",
  "cveTags": [],
  "metrics": {
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        "source": "nvd@nist.gov",
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          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:S/C:P/I:P/A:N",
          "authentication": "SINGLE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "PARTIAL"
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        "acInsufInfo": false,
        "impactScore": 4.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8,
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        "userInteractionRequired": false
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    "cvssMetricV31": [
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "HIGH"
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      "affectedData": [
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      "source": "support@hackerone.com"
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  "vulnStatus": "Modified",
  "weaknesses": [
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      "description": [
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          "value": "CWE-284"
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    {
      "type": "Primary",
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      "description": [
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A missing user check in Nextcloud prior to 20.0.6 inadvertently populates a user's own credentials for other users external storage configuration when not already configured yet."
    },
    {
      "lang": "es",
      "value": "Una falta de comprobación de usuario en Nextcloud versiones anteriores a 20.0.6, inadvertidamente llena las propias credenciales del usuario para la configuración del almacenamiento externo de otros usuarios cuando aún no están configuradas"
    }
  ],
  "lastModified": "2026-06-17T03:37:55.910",
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}