CVE-2021-32766: Nextcloud Text app can disclose existence of folders in "File Drop" link share

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-07 · updated 2026-06-17
Weakness: CWE-209

Description

Nextcloud Text is an open source plaintext editing application which ships with the nextcloud server. In affected versions the Nextcloud Text application returned different error messages depending on whether a folder existed in a public link share. This is problematic in case the public link share has been created with "Upload Only" privileges. (aka "File Drop"). A link share recipient is not expected to see which folders or files exist in a "File Drop" share. Using this vulnerability an attacker is able to enumerate folders in such a share. Exploitation requires that the attacker has access to a valid affected "File Drop" link share. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.0.1. Users who are unable to upgrade are advised to disable the Nextcloud Text application in the app settings.

Affected products

Nextcloud Server: before 20.0.12; from 21.0.0 before 21.0.4; from 22.0.0 before 22.1.0 — fixed in 20.0.12, 21.0.4, 22.1.0

How to fix

Upgrade to a fixed version: Nextcloud Server 20.0.12, 21.0.4, 22.1.0. Check the vendor advisory for mitigations.

References

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