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
If you have any questions or comments about this advisory:
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
If you have any questions or comments about this advisory: