CVE-2021-39794 : Exploit Details and Defense Strategies

This CVE-2021-39794 article provides insights into a security vulnerability affecting Android devices.

Understanding CVE-2021-39794

This section delves into the details of the vulnerability identified as CVE-2021-39794.

What is CVE-2021-39794?

CVE-2021-39794 is a vulnerability in broadcastPortInfo of AdbService.java that allows apps to execute code as the shell user, potentially leading to local privilege escalation. This can occur if wireless debugging is enabled without the necessary permission check.

The Impact of CVE-2021-39794

The vulnerability could result in local escalation of privilege without requiring extra execution privileges, necessitating user interaction for exploitation.

Technical Details of CVE-2021-39794

This section provides technical specifics of CVE-2021-39794.

Vulnerability Description

The flaw in broadcastPortInfo of AdbService.java permits apps to operate as the shell user under specific conditions.

Affected Systems and Versions

Product: Android
Versions: Android-11, Android-12, Android-12L

Exploitation Mechanism

The vulnerability arises when wireless debugging is enabled without the essential permission verification, enabling apps to run code as the shell user.

Mitigation and Prevention

Explore the measures to address CVE-2021-39794.

Immediate Steps to Take

Disable wireless debugging when not required
Regularly update the Android operating system
Avoid installing apps from untrusted sources

Long-Term Security Practices

Implement strong app permission policies
Educate users on safe device usage practices

Patching and Updates

Apply security patches promptly
Stay informed about Android security updates from official sources