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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


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.


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


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.

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