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Bypass lock protection in Android app (NC-SA-2019-006)

26th July 2019

Risk level: Low

CVSS v3 Base Score: 3.2 (AV:P/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N)

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

HackerOne report: 331489


If an attacker has physical access to an Android smartphone without a screen lock, but with nextcloud installed and set up, they can easily access the nextcloud-files even if the nextcloud app is locked with a fingerprint or pin.

Affected Software

  • Nextcloud Android < 3.3.0 (CVE-2019-5453)

Action Taken

The error has been fixed.


It is recommended that users upgrade to version 3.3.0 or later.


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

  • Volker Weißmann ( - Vulnerability discovery and disclosure.

This advisory is licensed CC BY-SA 4.0.

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