CVE-2021-32679

What it is

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`.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account, but needs a user to act. Limited direct impact.

Exploit odds

1.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-07-12 13:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:53 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.4% in the next 30 days (EPSS).
• Severity: 3.5 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-07-12 13:15 UTC

Last modified

2026-06-17 03:53 UTC

Exploit probability

1.4% · EPSS, next 30 days

Weakness

CWE-116

Record status

Modified

Affected

• Nextcloud Server < 19.0.13
• Nextcloud Server < 20.0.11
• Nextcloud Server < 21.0.3
• Fedoraproject Fedora 33
• Fedoraproject Fedora 34

Attack profile CVSS 3.1 · 3.5

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-32679.md and follow it. Check whether this project is affected by CVE-2021-32679. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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