Vulnerability Report

CVE-2021-32728

Title: Nextcloud Desktop Client private key validation bypass

Information Disclosure

Proof Of Concept

No public PoC currently indexed for CVE-2021-32728.

CWE Category CWE-295
Published Date Aug 18, 2021
Modified Date Nov 21, 2024
Exploit Status Not Found
Score 6.5 CVSS v3.1
Exploit Probability (EPSS)
0.85%

Vulnerability Summary

CVE-2021-32728: 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.

Impacted Vendors

A
avira 1
G
google 1
N
nextcloud 1

Reference Links

https://github.com/nextcloud/desktop/pull/3338 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5 https://hackerone.com/reports/1189162 https://www.debian.org/security/2021/dsa-4974 https://github.com/nextcloud/desktop/pull/3338 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5 https://hackerone.com/reports/1189162 https://www.debian.org/security/2021/dsa-4974
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
4.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:S/C:P/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-32728 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected Stack

No specific products linked.