22nd October 2019
Risk level: Low
CVSS v3 Base Score: 5 (AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N)
CWE: Improper Authorization (CWE-285)
HackerOne report: 719426
Improper authorization in Nextcloud server 17.0.0 causes leaking of previews and files when a file-drop share link is opened via the gallery app.
The error has been fixed.
It is recommended that the Nextcloud server is upgraded to 17.0.1.
The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory: