---
cve: "CVE-2021-37617"
severity: "HIGH"
cvss: 7.3
epss: "0.5%"
vendor: "nextcloud"
kev: false
exploited: false
published: "2021-08-18 18:15:08"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T03:52:13+02:00"
---

# CVE-2021-37617

> 7.3 HIGH · 🧪 PoC

## Beschreibung

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-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Erforderlich | good |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- acf3bf0959fc83393b71fbeed5b7633cab0f0d9d (Commit)

## Referenzen

- <https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q2w-v879-q24v>
- <https://github.com/nextcloud/desktop/pull/3497>
- <https://hackerone.com/reports/1240749>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-37617) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_