CVE-2021-39808 : Security Advisory and Response

This CVE-2021-39808 relates to a security issue in Android that allows a service to run in the foreground without user notification, potentially leading to privilege escalation.

Understanding CVE-2021-39808

CVE-2021-39808 is classified as an elevation of privilege vulnerability in Android.

What is CVE-2021-39808?

In the createNotificationChannelGroup of PreferencesHelper.java, improper input validation allows a service to run in the foreground without user notification, leading to local privilege escalation without needing additional privileges or user interaction.

The Impact of CVE-2021-39808

This vulnerability could be exploited to achieve local privilege escalation without the need for user interaction, posing a risk of unauthorized access to sensitive data.

Technical Details of CVE-2021-39808

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability lies in createNotificationChannelGroup of PreferencesHelper.java, enabling a service to run in the foreground without proper user notification.

Affected Systems and Versions

Affected Product: Android
Affected Versions: Android-10, Android-11, Android-12

Exploitation Mechanism

The vulnerability can be exploited by leveraging the improper input validation in PreferencesHelper.java to allow a service to operate in the foreground without proper user notification.

Mitigation and Prevention

To address CVE-2021-39808, follow the mitigation strategies outlined below.

Immediate Steps to Take

Regularly monitor for security updates from Android.
Implement the latest security patches provided by the vendor.
Restrict unnecessary permissions for applications.

Long-Term Security Practices

Conduct regular security assessments and audits.
Train users and developers on secure coding practices.

Patching and Updates

Stay updated on security advisories and promptly apply patches released by Android to mitigate the vulnerability.