CVE-2021-32766: Nextcloud Text app can disclose existence of folders in "File Drop" link share
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 Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2021-32766?
CVE-2021-32766 has a medium severity rating due to its potential to expose sensitive information through inconsistent error messages.
How do I fix CVE-2021-32766?
To mitigate CVE-2021-32766, it is recommended to upgrade Nextcloud Server to version 20.0.12 or later, or to any version from 21.0.5 onward.
Which versions of Nextcloud are affected by CVE-2021-32766?
CVE-2021-32766 affects Nextcloud Server versions up to 20.0.11, as well as versions from 21.0.0 to 21.0.4 and from 22.0.0 to 22.1.0.
Is CVE-2021-32766 a remote code execution vulnerability?
No, CVE-2021-32766 is not a remote code execution vulnerability; it primarily involves information disclosure due to improper error handling.
What risk does CVE-2021-32766 pose to my Nextcloud installation?
CVE-2021-32766 poses a risk of information disclosure that could lead to unauthorized access to shared files or data in Nextcloud.