TI-2021-12347 Aliases CVE-2021-32679

Filenames not escaped by default in controllers using DownloadResponse

MEDIUM 41CWE-116Published 2021-07-12 · Updated 2024-08-03

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

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`.

Why it matters now

EPSS 0.0137 72nd percentileScored 2026-11-07

Fix Fixed security-advisories (nextcloud): 19.0.13, 20.0.11, 21.0.3

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
nextcloud	security-advisories	before 19.0.13; 20.0.0 to before 20.0.11; 21.0.0 to before 21.0.3	19.0.13, 20.0.11, 21.0.3	Patch available	CNA

security-advisories Vendornextcloud Affected before 19.0.13; 20.0.0 to before 20.0.11; 21.0.0 to before 21.0.3 Fixed in 19.0.13, 20.0.11, 21.0.3 Patch available CNA

CPE configurations NVD · 3

CPE	Versions	Role	Vendor
cpe:2.3:a:nextcloud:nextcloud_server::::::::	before 19.0.13; 20.0.0 to before 20.0.11; 21.0.0 to before 21.0.3	Vulnerable	nextcloud
cpe:2.3:o:fedoraproject:fedora:33:::::::*	33	Vulnerable	Fedoraproject
cpe:2.3:o:fedoraproject:fedora:34:::::::*	34	Vulnerable	Fedoraproject

cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:* Versions before 19.0.13; 20.0.0 to before 20.0.11; 21.0.0 to before 21.0.3 Vulnerable ·nextcloud
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject

Remediation

Fix · CNA security-advisories (nextcloud) Fixed in 19.0.13, 20.0.11, 21.0.3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Advisory · 2021-07-12
nextcloud security-advisories — FEDORA-2021-6f327296fe
6 records Highest priority Priority MEDIUM 2 MEDIUM, 4 LOW
Other records, highest priority first
- TI-2021-12356 Application specific tokens can change their own scopePriority MEDIUM 42
- TI-2021-12373 Lack of ratelimit on public DAV endpointPriority LOW 36
- TI-2021-12371 Lack of ratelimit on shareinfo endpointPriority LOW 27
Show all 6 records → Advisory →
Advisory · 2021-07-12
nextcloud security-advisories — FEDORA-2021-9b421b78af
6 records Highest priority Priority MEDIUM 2 MEDIUM, 4 LOW
Other records, highest priority first
- TI-2021-12356 Application specific tokens can change their own scopePriority MEDIUM 42
- TI-2021-12373 Lack of ratelimit on public DAV endpointPriority LOW 36
- TI-2021-12371 Lack of ratelimit on shareinfo endpointPriority LOW 27
Show all 6 records → Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2021-32679

References

Patch 1

https://github.com/nextcloud/server/pull/27354

Advisory 4

Other 1

https://hackerone.com/reports/1215263

TI-2023-20855 Users can delete external storage mount points CVSS 3.1HIGH 7.7
TI-2023-11091 Nextcloud download permissions can be changed by resharer CVSS 3.1HIGH 7.5
TI-2023-10624 Nextcloud Server vulnerable to SSRF via filter bypass due to lax checking on IPs CVSS 3.1MEDIUM 5.3
TI-2025-37238 Cross-site scripting in Nextcloud CVSS 3.1MEDIUM 6.4
TI-2023-11086 nextcloud vulnerable to Uncontrolled Resource Consumption CVSS 3.1MEDIUM 6.5
TI-2022-18738 Exception logging in Sharepoint app reveals clear-text connection details CVSS 3.1MEDIUM 6.5

See all 188 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences