Workflow rules only check the file extension for the mimetype instead of the content (NC-SA-2020-002)
4th December 2019
Risk level: Low
CVSS v3 Base Score: 5.5 (AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L)
HackerOne report: 697959
A bug in Nextcloud Server 17.0.1 causes the workflow rules to depend their behaviour on the file extension when checking file mimetypes.
- Nextcloud Server < 17.0.2 (CVE-2019-15613)
- Nextcloud Server < 16.0.7 (CVE-2019-15613)
- Nextcloud Server < 15.0.14 (CVE-2019-15613)
The error has been fixed.
It is recommended that the Nextcloud Server is upgraded to 17.0.2.
The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory:
- Ralf Thesing - Vulnerability discovery and disclosure.
This advisory is licensed CC BY-SA 4.0.