CVEvulnerability
CVE-2021-32679
8.8 HIGH
Official page ↗
- Status
- Modified
- Published
- 2021-07-12
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 3.5 LOW — CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
- CVSS 3.1 ([email protected])
- 8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CVSS 2.0 ([email protected])
- 6.8 MEDIUM — AV:N/AC:M/Au:N/C:P/I:P/A:P
- Weaknesses
- CWE-116
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`.
Affected configurations
• nextcloud nextcloud server (< 19.0.13)
• nextcloud nextcloud server (>= 20.0.0 < 20.0.11)
• nextcloud nextcloud server (>= 21.0.0 < 21.0.3)
• fedoraproject fedora 33
• fedoraproject fedora 34
Related
Weakness · CWE (1)
- CWE-116 Improper Encoding or Escaping of Output weakness
References
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3hjp-26x8-mhf6 Third Party Advisory
- https://github.com/nextcloud/server/pull/27354 Patch, Third Party Advisory
- https://hackerone.com/reports/1215263 Permissions Required
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BVZS26RDME2DYTKET5AECRIZDFUGR2AZ/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J63NBVPR2AQCAWRNDOZSGRY5II4WS2CZ/ lists.fedoraproject.org
- https://security.gentoo.org/glsa/202208-17 Third Party Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3hjp-26x8-mhf6 Third Party Advisory
- https://github.com/nextcloud/server/pull/27354 Patch, Third Party Advisory
- https://hackerone.com/reports/1215263 Permissions Required
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BVZS26RDME2DYTKET5AECRIZDFUGR2AZ/ lists.fedoraproject.org
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J63NBVPR2AQCAWRNDOZSGRY5II4WS2CZ/ lists.fedoraproject.org
- https://security.gentoo.org/glsa/202208-17 Third Party Advisory