CVE-2021-37617 Untrusted Search Path in Nextcloud Desktop Client
A malicious user can execute arbitrary code with administrative privileges by placing a malicious Uninstall.exe in a writable directory during installation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-37617?
CVE-2021-37617 is a high-severity vulnerability in nextcloud security-advisories, published on 18 Aug 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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.
Which versions are affected by CVE-2021-37617?
It affects 1 product.
Products include Nextcloud Desktop.
How do I fix CVE-2021-37617?
No fix has been published for CVE-2021-37617 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-37617 being exploited?
There is no known exploitation of CVE-2021-37617 in the wild and no public exploit code.
Other vulnerabilities in nextcloud security-advisories
- CVE-2024-46958 Misconfiguration in n/a
- CVE-2020-8224 Code injection in Desktop Client
- CVE-2020-8225 Information disclosure in Desktop Client
- CVE-2023-28999 Nextcloud: Lack of authenticity of metadata keys allows a malicious server to gain access to E2EE folders
- CVE-2020-8227 Path traversal in Desktop Client
Sources
Also known as GHSA-6q2w-v879-q24v.