CVE-2021-37617

Untrusted Search Path in Nextcloud Desktop Client

CVSS 7.3 HIGHEPSS 0.5%CWE-426

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.3EPSS 0.5%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

18 Aug 2021Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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

Affected products

nextcloud · security-advisories

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References

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