CVE-2021-32679

 

Published at: - 12-07-2021 03:15

Last modified: - 26-10-2022 04:10

Total changes: - 7

Description

Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.0.11, and 21.0.3, filenames where not escaped by default in controllers using `DownloadResponse`. When a user-supplied filename was passed unsanitized into a `DownloadResponse`, this could be used to trick users into downloading malicious files with a benign file extension. This would show in UI behaviours where Nextcloud applications would display a benign file extension (e.g. JPEG), but the file will actually be downloaded with an executable file extension. The vulnerability is patched in versions 19.0.13, 20.0.11, and 21.0.3. Administrators of Nextcloud instances do not have a workaround available, but developers of Nextcloud apps may manually escape the file name before passing it into `DownloadResponse`.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

 

Verification logic

 

Reference

• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3hjp-26x8-mhf6
• https://hackerone.com/reports/1215263
• https://github.com/nextcloud/server/pull/27354
• FEDORA-2021-9b421b78af-Mailing List, Third Party Advisory
• FEDORA-2021-6f327296fe-Mailing List, Third Party Advisory
• GLSA-202208-17-Third Party Advisory

 

Keywords

NVD

 

CVE-2021-32679

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures