High severity · published Aug 18, 2021
CVE-2021-37617
The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer
7.3
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 39% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DE
Desktop · Nextcloud
3.0.3 before 3.3.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-37617
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-37617
Patch
https://github.com/nextcloud/desktop/pull/3497
Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q2w-v879-q24v
Permissions Required
https://hackerone.com/reports/1240749
More from Desktop
9.1
CVE-2024-46958
In Nextcloud Desktop Client 3.13.1 through 3.13.3 on Linux, synchronized files (between the server and client) may become world writable or world readable
8.8
CVE-2023-22472
Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud
8.8
CVE-2021-22879
Nextcloud Desktop Client prior to 3.1.3 is vulnerable to resource injection by way of missing validation of URLs, allowing a malicious server to execute remote commands
7.8
CVE-2024-37885
The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with your computer
7.8
CVE-2022-41882
The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with your computer