CVE-2022-41926 - Nextcloud Talk Android Unprotected Broadcast Receiver Vulnerability and Its Resolution

Nextcloud Talk Android is the widely used Android OS implementation of the Nextcloud Talk chat system, allowing users to communicate securely and seamlessly. However, a recent vulnerability – registered as CVE-2022-41926 – has been discovered in certain versions of the Nextcloud Talk Android application, compromising the app's security measures by leaving the receiver unprotected.

This vulnerability allows malicious apps to monitor users' communication, effectively turning the Nextcloud Talk chat platform into a playground for cyber attackers. In light of this significant security risk, it is highly recommended that users upgrade their Nextcloud Talk Android applications to version 14.1. as soon as possible to mitigate the threat.

Vulnerability Details

The CVE-2022-41926 vulnerability stems from the lack of proper protection for the broadcast receiver in affected versions of Nextcloud Talk Android. As a result, malicious apps can intercept the communication and eavesdrop on users' messages.

The vulnerable code snippet is as follows

<receiver
    android:name=".NotificationBroadcastReceiver"
    android:exported="true"> // The receiver should not be marked as exported.
    <intent-filter>
        <action android:name="com.nextcloud.talk.notification.ACTION_CLEAR" />
    </intent-filter>
</receiver>

This code snippet comes from the AndroidManifest.xml file, which contains vital information about the app's components. The lack of proper security settings in the code allows other apps to access the receiver, thereby permitting potential eavesdropping attempts.

To fix this vulnerability, the android:exported attribute should be set to "false" instead of "true," as shown in the following corrected code snippet:

<receiver
    android:name=".NotificationBroadcastReceiver"
    android:exported="false"> // The receiver should be marked as not exported.
    <intent-filter>
        <action android:name="com.nextcloud.talk.notification.ACTION_CLEAR" />
    </intent-filter>
</receiver>

References

- Nextcloud: Nextcloud Security Advisory
- National Vulnerability Database: CVE-2022-41926

Recommended Actions

To mitigate the threat posed by the CVE-2022-41926 vulnerability, users are strongly encouraged to upgrade their Nextcloud Talk Android applications to version 14.1.. This can be done by visiting the Google Play Store and updating the app to the latest release.

Unfortunately, there are no known workarounds for this issue. Therefore, the safest course of action is to update the Nextcloud Talk Android application as promptly as possible to safeguard your communication from potential eavesdropping attempts.

Conclusion

The CVE-2022-41926 vulnerability in the Nextcloud Talk Android application poses a significant threat to users' security and privacy. Without the necessary security measures in place, malicious apps can easily intercept and monitor their communication, leading to potential data breaches and other critical consequences. The most effective response to this vulnerability is to upgrade the Nextcloud Talk Android application to version 14.1., ensuring that your private conversations remain secure from prying eyes.

Timeline

Published on: 11/25/2022 19:15:00 UTC
Last modified on: 12/01/2022 14:45:00 UTC