Vulnerability Report

CVE-2021-37617

Title: Privilege Escalation in Nextcloud Desktop Client Uninstaller

Privilege Escalation

Proof Of Concept

No public PoC currently indexed for CVE-2021-37617.

CWE Category CWE-427
Published Date Aug 18, 2021
Modified Date Nov 21, 2024
Exploit Status Not Found
Score 7.3 CVSS v3.1
Exploit Probability (EPSS)
0.46%

Vulnerability Summary

CVE-2021-37617: The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. The Nextcloud Desktop Client invokes its uninstaller script when being installed to make sure there are no remnants of previous installations. In versions 3.0.3 through 3.2.4, the Client searches the `Uninstall.exe` file in a folder that can be written by regular users. This could lead to a case where a malicious user creates a malicious `Uninstall.exe`, which would be executed with administrative privileges on the Nextcloud Desktop Client installation. This issue is fixed in Nextcloud Desktop Client version 3.3.0. As a workaround, do not allow untrusted users to create content in the `C:\` system folder and verify that there is no malicious `C:\Uninstall.exe` file on the system.

Impacted Vendors

A
avira 1
G
google 1
N
nextcloud 1

Reference Links

https://github.com/nextcloud/desktop/pull/3497 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q2w-v879-q24v https://hackerone.com/reports/1240749 https://github.com/nextcloud/desktop/pull/3497 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q2w-v879-q24v https://hackerone.com/reports/1240749
CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.3
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.3
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
4.4
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:L/AC:M/Au:N/C:P/I:P/A:P

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-37617 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 LOCAL
Complexity LOW
Privileges N/A
Interaction REQUIRED
CVSS Vector String CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.