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

2021-08-1816:00:13

CWE-295

GitHub_M

www.cve.org

6.5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

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

6.4 Medium

AI Score

Confidence

High

0.004 Low

EPSS

Percentile

74.6%

JSON

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.

CNA Affected

[
  {
    "product": "security-advisories",
    "vendor": "nextcloud",
    "versions": [
      {
        "status": "affected",
        "version": "< 3.3.0"
      }
    ]
  }
]