{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.16.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5b68a3a475acd0378f91f44dd5eedd79a454b952"
            }
          ],
          "repo": "https://github.com/nextcloud/android",
          "type": "GIT"
        }
      ]
    }
  ],
  "details": "Nextcloud Android Client is the Android client for Nextcloud. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.16.1, the Nextcloud Android client skipped a step that involved the client checking if a private key belonged to a previously downloaded public certificate. If the Nextcloud instance served a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. The vulnerability is patched in version 3.16.1. As a workaround, do not add additional end-to-end encrypted devices to a user account.",
  "id": "CVE-2021-32727",
  "modified": "2026-04-01T23:09:21.980792566Z",
  "published": "2021-07-12T21:15:07.817Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/nextcloud/android/pull/8438"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nextcloud/end_to_end_encryption_rfc/blob/7f002996397faefb664019a97ebb0a1e210f64f0/RFC.md#further-devices"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-5v33-r9cm-7736"
    },
    {
      "type": "REPORT",
      "url": "https://hackerone.com/reports/1189162"
    }
  ],
  "related": [
    "GHSA-5v33-r9cm-7736"
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}