Vulnerability · Published Aug 18, 2021 · Assigned by GitHub_M
CVE-2021-37617Untrusted Search Path in Nextcloud Desktop Client
High 7.3
In plain English
A high-severity security flaw in security-advisories from nextcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| nextcloud | security-advisories | >= 3.0.3 , <= 3.2.4 |
Weakness: CWE-426 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
References
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q2w-v879-q24v x_refsource_CONFIRM
- https://github.com/nextcloud/desktop/pull/3497 x_refsource_MISC
- https://hackerone.com/reports/1240749 x_refsource_MISC