25th October 2018
Risk level: Low
CVSS v3 Base Score: 6.4 (AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N)
CWE: Improper Access Control - Generic (CWE-284)
HackerOne report: 388515
Improper revalidation of permissions lead to not accepting access restrictions by acess tokens.
The error has been fixed.
It is recommended that all instances are upgraded to Nextcloud 14.0.0, Nextcloud 13.0.6 or Nextcloud 12.0.11.
The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory: