Security Advisory

Bypass lock protection in Android app (NC-SA-2020-004)

5th December 2019

Risk level: Low

CVSS v3 Base Score: 5.9 (AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N)

CWE: Authentication Bypass Using an Alternate Path or Channel (CWE-288)

HackerOne report: 747726

Description

A wrong check for the system time in the Android App 3.9.0 causes a bypass of the lock protection when changing the time of the system to the past.

Affected Software

• Nextcloud Android < 3.9.1 (CVE-2019-15615)

Action Taken

The error has been fixed.

Resolution

It is recommended that the Android App is upgraded to 3.9.1.

Acknowledgements

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

• Arvind (ar-arvind@protonmail.com) - Vulnerability discovery and disclosure.

This advisory is licensed CC BY-SA 4.0.