Bypassing quota limitation (NC-SA-2017-005)

5th February 2017

Risk level: Low

CVSS v3 Base Score: 0 (AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:N)

CWE: Reliance on Untrusted Inputs in a Security Decision (CWE-807)

HackerOne report: 173622

Description

Due to not properly sanitzing values provided by the `OC-Total-Length` HTTP header an authenticated adversary may be able to exceed their configured user quota. Thus using more space than allowed by the administrator.

Affected Software

Nextcloud Server < 10.0.2 (CVE-2017-0887)
Nextcloud Server < 9.0.55 (CVE-2017-0887)

Action Taken

The `OC-Total-Length` HTTP header is now properly sanitized.

Resolution

It is recommended that all instances are upgraded to Nextcloud 9.0.55 or 10.0.2.

Acknowledgements

The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory:

Nordin - Vulnerability discovery and disclosure.

This advisory is licensed CC BY-SA 4.0.

Security Advisory