HexBrain

Nextcloud · Report #1784645

Passcode bypass on Talk Android app

Validstatus
lowseverity
30upvotes
9 Jan 2023disclosed

Summary

Security advisory at https://github.com/nextcloud/security-advisories/security/advisories/GHSA-wvr4-gc4c-6vmx

How it was found

Summary:

It is possible to bypass the passcode protection in nextcloud android talk by clicking the notification of a message.

Talk App Android version: 15.0.2 RC1

Steps To Reproduce:

  1. Create two users
  2. Using User A login it to the web interface while User B on Talk App Android
  3. Using User B setup the passcode protection in settings
  4. Using User A send a message to User B
  5. Wait for the notification and click it

Supporting Material/References:

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Impact

To exploit this the attacker needs to have a physical access to the target's device which makes it severity to medium. Due to the bypass of passcode an attacker is able to access the user's nextcloud files and view conversations.

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This report was disclosed publicly on HackerOne and belongs to its author and the program. See the original