Vulnerability-Lookup

FKIE_CVE-2021-41239

Vulnerability from fkie_nvd - Published: 2022-03-08 18:15 - Updated: 2026-06-17 04:08

Severity

5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Summary

Nextcloud server is a self hosted system designed to provide cloud style services. In affected versions the User Status API did not consider the user enumeration settings by the administrator. This allowed a user to enumerate other users on the instance, even when user listings where disabled. It is recommended that the Nextcloud Server is upgraded to 20.0.14, 21.0.6 or 22.2.1. There are no known workarounds.

References

URL	Tags
security-advisories@github.com	https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrx	Issue Tracking, Third Party Advisory
security-advisories@github.com	https://github.com/nextcloud/server/issues/27122	Issue Tracking, Patch, Third Party Advisory
security-advisories@github.com	https://github.com/nextcloud/server/pull/29260	Patch, Third Party Advisory
security-advisories@github.com	https://security.gentoo.org/glsa/202208-17	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrx	Issue Tracking, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/nextcloud/server/issues/27122	Issue Tracking, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/nextcloud/server/pull/29260	Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://security.gentoo.org/glsa/202208-17	Third Party Advisory

Impacted products

Vendor	Product	Version
nextcloud	nextcloud_server	*
nextcloud	nextcloud_server	*
nextcloud	nextcloud_server	22.2.0

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "security-advisories",
          "vendor": "nextcloud",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 20.0.14"
            },
            {
              "status": "affected",
              "version": "\u003e= 21.0.0, \u003c 21.0.6"
            },
            {
              "status": "affected",
              "version": "\u003e= 22.2.0, \u003c 22.2.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "FE354750-B4B3-4F0A-8B59-472C527BC7B2",
              "versionEndExcluding": "20.0.14",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "467AE8CC-B050-4A69-AD8A-88C71C69C898",
              "versionEndExcluding": "21.0.6",
              "versionStartIncluding": "21.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:nextcloud_server:22.2.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "0FB174BF-D3FD-49C6-B216-3166DE1AD6F9",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Nextcloud server is a self hosted system designed to provide cloud style services. In affected versions the User Status API did not consider the user enumeration settings by the administrator. This allowed a user to enumerate other users on the instance, even when user listings where disabled. It is recommended that the Nextcloud Server is upgraded to 20.0.14, 21.0.6 or 22.2.1. There are no known workarounds."
    },
    {
      "lang": "es",
      "value": "Nextcloud server es un sistema auto-alojado dise\u00f1ado para proporcionar servicios de estilo en la nube. En las versiones afectadas, la API de estado de usuario no ten\u00eda en cuenta la configuraci\u00f3n de enumeraci\u00f3n de usuarios por parte del administrador. Esto permit\u00eda a un usuario enumerar a otros usuarios en la instancia, incluso cuando los listados de usuarios estaban deshabilitados. Es recomendado actualizar el servidor Nextcloud a versiones 20.0.14, 21.0.6 o 22.2.1. No se presentan medidas de mitigaci\u00f3n conocidas"
    }
  ],
  "id": "CVE-2021-41239",
  "lastModified": "2026-06-17T04:08:09.197",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 5.0,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "NONE",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-41239",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
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          "role": "CISA Coordinator",
          "timestamp": "2025-04-23T15:57:02.638564Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2022-03-08T18:15:07.873",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking",
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      ],
      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrx"
    },
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      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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        "Third Party Advisory"
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      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrx"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Issue Tracking",
        "Patch",
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      "url": "https://github.com/nextcloud/server/issues/27122"
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    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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        "Third Party Advisory"
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      "url": "https://github.com/nextcloud/server/pull/29260"
    },
    {
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  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
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      "description": [
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      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-862"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2021-41239 (GCVE-0-2021-41239)

Vulnerability from cvelistv5 – Published: 2022-03-08 18:05 – Updated: 2025-04-23 18:58

Title

User enumeration setting not respected in Nextcloud server

Summary

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-04-23 15:57 UTC

CWE

CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7612 records in the last 180 days details

References

4 references

URL	Tags
https://github.com/nextcloud/security-advisories/…	x_refsource_CONFIRM
https://github.com/nextcloud/server/issues/27122	x_refsource_MISC
https://github.com/nextcloud/server/pull/29260	x_refsource_MISC
https://security.gentoo.org/glsa/202208-17	vendor-advisoryx_refsource_GENTOO

Impacted products

1 product

Vendor	Product	Version
nextcloud	security-advisories	Affected: < 20.0.14 Affected: >= 21.0.0, < 21.0.6 Affected: >= 22.2.0, < 22.2.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T03:08:31.486Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
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        "references": [
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            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrx"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/nextcloud/server/issues/27122"
          },
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            "tags": [
              "x_refsource_MISC",
              "x_transferred"
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            "url": "https://github.com/nextcloud/server/pull/29260"
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              "x_refsource_GENTOO",
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            "url": "https://security.gentoo.org/glsa/202208-17"
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        ],
        "title": "CVE Program Container"
      },
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        "metrics": [
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                "options": [
                  {
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                "role": "CISA Coordinator",
                "timestamp": "2025-04-23T15:57:02.638564Z",
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        "providerMetadata": {
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          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
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          "product": "security-advisories",
          "vendor": "nextcloud",
          "versions": [
            {
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              "version": "\u003c 20.0.14"
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        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
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            "baseSeverity": "MEDIUM",
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        },
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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