CVE-2021-37617
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.3 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 0.46% probability · 38th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-426, CWE-427
- Affected
- nextcloud/desktop
- Source
- security-advisories@github.com
References
- https://github.com/nextcloud/desktop/pull/3497Patch, Third Party Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q2w-v879-q24vThird Party Advisory
- https://hackerone.com/reports/1240749Permissions Required, Third Party Advisory
- https://github.com/nextcloud/desktop/pull/3497Patch, Third Party Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q2w-v879-q24vThird Party Advisory
- https://hackerone.com/reports/1240749Permissions Required, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.