Vulnerability in Nextcloud Desktop
CVE-2021-37617
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.
EPSS: 0.005 (38.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Nextcloud Desktop
- Nextcloud Security-advisories — versions >= 3.0.3 , <= 3.2.4
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Permissions Required, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-37617?
- CVE-2021-37617 is a high-severity vulnerability in Nextcloud Desktop, classified under Untrusted Search Path. CVSS score: 7.3/10. Published 2021-08-18.
- How severe is CVE-2021-37617?
- High severity. CVSS v3 base score is 7.3 out of 10.