Description
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.
Metrics
CVSS 3.1 7.5/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| nextcloud | security-advisories | < 3.16.1 |
References
- https://github.com/nextcloud/android/pull/8438Third Party Advisory
- https://github.com/nextcloud/end_to_end_encryption_rfc/blob/7f002996397faefb664019a97ebb0a1e210f64f0/RFC.md#further-devicesThird Party Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-5v33-r9cm-7736Third Party Advisory
- https://hackerone.com/reports/1189162Permissions Required
- https://github.com/nextcloud/android/pull/8438Third Party Advisory
- https://github.com/nextcloud/end_to_end_encryption_rfc/blob/7f002996397faefb664019a97ebb0a1e210f64f0/RFC.md#further-devicesThird Party Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-5v33-r9cm-7736Third Party Advisory
- https://hackerone.com/reports/1189162Permissions Required
Timeline
- Published
- Jul 12, 2021
- Last modified
- Jun 17, 2026
- NVD status
- Modified