Potential DDoS when posting long data into workflow validation rules (NC-SA-2021-001)
18th November 2020
Risk level: Low
CVSS v3 Base Score: 5.7 (AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H)
HackerOne report: 1018146
A missing input validation in Nextcloud Server 20.0.1 allowed users to store unlimited data in workflow rules causing load and potential DDoS on later interactions and usage with those rules.
- Nextcloud Server < 20.0.2 (CVE-2020-8293)
- Nextcloud Server < 19.0.5 (CVE-2020-8293)
- Nextcloud Server < 18.0.11 (CVE-2020-8293)
The error has been fixed.
It is recommended that the Nextcloud Server is upgraded to 20.0.2.
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.