UBUNTU-CVE-2021-32728 (CVE-2021-32728)

Vulnerability from osv_ubuntu – Published: 2021-08-18 16:15 – Updated: 2026-04-22 07:40 – Source website
VLAI
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
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"
  ]
}



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