CVE-2021-37617

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-08-18 18:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:00 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 7.3 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-08-18 18:15 UTC

Last modified

2026-06-17 04:00 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-426

Record status

Modified

Affected

• Nextcloud Desktop < 3.3.0

Attack profile CVSS 3.1 · 7.3

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-37617.md and follow it. Check whether this project is affected by CVE-2021-37617. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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