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Nextcloud Text app can disclose existence of folders in "File Drop" link share

Low
LukasReschke published GHSA-gcf3-3wmc-88jr Sep 6, 2021

Package

Nextcloud Server

Affected versions

< 20.0.12, < 21.0.4, < 22.1.0

Patched versions

20.0.12, 21.0.4, 22.1.0

Description

Impact

The Nextcloud Text application shipped with Nextcloud Server 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.

Patches

It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0

Workarounds

Disable the Nextcloud Text application in the app settings.

References

For more information

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Severity

Low

CVE ID

CVE-2021-32766

Weaknesses

Credits