Security Advisory

PIN for passwordless WebAuthn is asked for but not verified (NC-SA-2020-037)

25th August 2020

Risk level: Low

CVSS v3 Base Score: 4.3 (AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)

CWE: Improper Authentication - Generic (CWE-287)

HackerOne report: 924393

Description

A wrong configuration in Nextcloud Server 19.0.1 incorrectly made the user feel the passwordless WebAuthn is also a two factor verification by asking for the PIN of the passwordless WebAuthn but not verifying it.

Affected Software

• Nextcloud Server < 19.0.2 (CVE-2020-8236)

Action Taken

The error has been fixed.

Resolution

It is recommended that the Nextcloud Server is upgraded to 19.0.2.

Acknowledgements

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

• Dominik Schürmann - COTECH (contact@cotech.de) - Vulnerability discovery and disclosure.

This advisory is licensed CC BY-SA 4.0.