10th October 2016
Risk level: Low
CVSS v3 Base Score: 3.1 (AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N)
CWE: User Interface (UI) Misrepresentation of Critical Information (CWE-451)
HackerOne report: 154827
The location bar in the files app was not verifying the passed parameters. An attacker could craft an invalid link to a fake directory structure and use this to display an attacker-controlled error message to the user.
The passed parameter is now verified.
It is recommended that all instances are upgraded to Nextcloud 9.0.54 or 10.0.1.
The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory: