CVE-2021-32728
Publication date 18 August 2021
Last updated 26 August 2025
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| nextcloud-desktop | 25.10 questing |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Not in release |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
6.5 · Medium
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | None |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |