CVE-2021-32728 MEDIUM

CVE-2021-32728: End-to-end encryption device setup did not verify public key

Vendor Nextcloud
Product security-advisories
Weakness CWE-295
Published August 18, 2021
Last update August 3, 2024

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

August 18, 2021 CVE published
August 3, 2024 Record updated