Error message discloses existence of file in write-only share (NC-SA-2017-003)
5th February 2017
Risk level: Low
CVSS v3 Base Score: 3.7 (AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:L)
HackerOne report: 174524
Due to an error in the application logic an adversary with access to a write-only share may enumerate the names of existing files and subfolders by comparing the exception messages.
- Nextcloud Server < 10.0.2 (CVE-2017-0885)
- Nextcloud Server < 9.0.55 (CVE-2017-0885)
The error in the application logic has been addressed.
It is recommended that all instances are upgraded to Nextcloud 9.0.55 or 10.0.2.
The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory:
This advisory is licensed CC BY-SA 4.0.