Vulnerability-Lookup

ubuntu-cve-2021-32728

Vulnerability from osv_ubuntu

Published

2021-08-18 16:15

Modified

2026-04-22 07:40

Summary

Details

The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.

Severity

6.5 (Medium)


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

6.5 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2021-32728	REPORT
	https://github.com/nextcloud/security-advisories/…	REPORT
	https://github.com/nextcloud/desktop/pull/3338	REPORT
	https://hackerone.com/reports/1189162	REPORT
	https://www.cve.org/CVERecord?id=CVE-2021-32728	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "caja-nextcloud",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "dolphin-nextcloud",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "libnextcloudsync0",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "nautilus-nextcloud",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "nemo-nextcloud",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "nextcloud-desktop",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "nextcloud-desktop-cmd",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "nextcloud-desktop-common",
            "binary_version": "2.6.2-1build1"
          },
          {
            "binary_name": "nextcloud-desktop-l10n",
            "binary_version": "2.6.2-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "nextcloud-desktop",
        "purl": "pkg:deb/ubuntu/nextcloud-desktop@2.6.2-1build1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.5.3-1",
        "2.6.0-1",
        "2.6.1-1",
        "2.6.1-2",
        "2.6.2-1",
        "2.6.2-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "caja-nextcloud",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "dolphin-nextcloud",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "libnextcloudsync0",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "nautilus-nextcloud",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "nemo-nextcloud",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "nextcloud-desktop",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "nextcloud-desktop-cmd",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "nextcloud-desktop-common",
            "binary_version": "3.4.2-1ubuntu1"
          },
          {
            "binary_name": "nextcloud-desktop-l10n",
            "binary_version": "3.4.2-1ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "nextcloud-desktop",
        "purl": "pkg:deb/ubuntu/nextcloud-desktop@3.4.2-1ubuntu1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.2.3-0ubuntu1",
        "3.3.5-1",
        "3.3.5-1ubuntu1",
        "3.4.2-1",
        "3.4.2-1ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.",
  "id": "UBUNTU-CVE-2021-32728",
  "modified": "2026-04-22T07:40:03Z",
  "published": "2021-08-18T16:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-32728"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/nextcloud/desktop/pull/3338"
    },
    {
      "type": "REPORT",
      "url": "https://hackerone.com/reports/1189162"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-32728"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-32728"
  ]
}

CVE-2021-32728 (GCVE-0-2021-32728)

Vulnerability from cvelistv5 – Published: 2021-08-18 16:00 – Updated: 2024-08-03 23:33

Title

End-to-end encryption device setup did not verify public key

Summary

Severity

6.5 (Medium)


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

CWE

CWE-295 - Improper Certificate Validation

Assigner

GitHub_M

References

4 references

URL	Tags
https://hackerone.com/reports/1189162	x_refsource_MISC
https://github.com/nextcloud/security-advisories/…	x_refsource_CONFIRM
https://github.com/nextcloud/desktop/pull/3338	x_refsource_MISC
https://www.debian.org/security/2021/dsa-4974	vendor-advisoryx_refsource_DEBIAN

Impacted products

1 product

Vendor	Product	Version
nextcloud	security-advisories	Affected: < 3.3.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T23:33:54.918Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://hackerone.com/reports/1189162"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/nextcloud/desktop/pull/3338"
          },
          {
            "name": "DSA-4974",
            "tags": [
              "vendor-advisory",
              "x_refsource_DEBIAN",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2021/dsa-4974"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "security-advisories",
          "vendor": "nextcloud",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.3.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-295",
              "description": "CWE-295: Improper Certificate Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-09-19T23:06:11.000Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://hackerone.com/reports/1189162"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nextcloud/desktop/pull/3338"
        },
        {
          "name": "DSA-4974",
          "tags": [
            "vendor-advisory",
            "x_refsource_DEBIAN"
          ],
          "url": "https://www.debian.org/security/2021/dsa-4974"
        }
      ],
      "source": {
        "advisory": "GHSA-f5fr-5gcv-6cc5",
        "discovery": "UNKNOWN"
      },
      "title": "End-to-end encryption device setup did not verify public key",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security-advisories@github.com",
          "ID": "CVE-2021-32728",
          "STATE": "PUBLIC",
          "TITLE": "End-to-end encryption device setup did not verify public key"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "security-advisories",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "\u003c 3.3.0"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "nextcloud"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading."
            }
          ]
        },
        "impact": {
          "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-295: Improper Certificate Validation"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://hackerone.com/reports/1189162",
              "refsource": "MISC",
              "url": "https://hackerone.com/reports/1189162"
            },
            {
              "name": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5",
              "refsource": "CONFIRM",
              "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5"
            },
            {
              "name": "https://github.com/nextcloud/desktop/pull/3338",
              "refsource": "MISC",
              "url": "https://github.com/nextcloud/desktop/pull/3338"
            },
            {
              "name": "DSA-4974",
              "refsource": "DEBIAN",
              "url": "https://www.debian.org/security/2021/dsa-4974"
            }
          ]
        },
        "source": {
          "advisory": "GHSA-f5fr-5gcv-6cc5",
          "discovery": "UNKNOWN"
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-32728",
    "datePublished": "2021-08-18T16:00:13.000Z",
    "dateReserved": "2021-05-12T00:00:00.000Z",
    "dateUpdated": "2024-08-03T23:33:54.918Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

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.

Detection rules are retrieved from Rulezet.

Action not permitted

ubuntu-cve-2021-32728

Vulnerability from osv_ubuntu

CVE-2021-32728 (GCVE-0-2021-32728)

Tags

Sightings

Nomenclature