CVE-2021-39806 Explained : Impact and Mitigation

Android-12L vulnerability leading to local privilege escalation.

Understanding CVE-2021-39806

A double free issue in Android-12L could allow an attacker to exploit and gain elevated privileges.

What is CVE-2021-39806?

Type: Elevation of privilege
Description: In label_backends_android.c, a double free can corrupt memory, enabling local privilege escalation during servicemanager startup without user interaction.

The Impact of CVE-2021-39806

An attacker can trigger an initialization failure to gain escalated privileges without additional execution rights.

Technical Details of CVE-2021-39806

A detailed look into the vulnerability.

Vulnerability Description

The vulnerability lies in Android-12L's label_backends_android.c, leading to memory corruption via a double free.

Affected Systems and Versions

Product: Android
Versions Affected: Android-12L

Exploitation Mechanism

To exploit, an attacker triggers an initialization failure during servicemanager startup, requiring no additional execution privileges.

Mitigation and Prevention

Steps to mitigate the CVE-2021-39806 vulnerability.

Immediate Steps to Take

Apply available patches promptly to secure the system.
Monitor official vendor sources for any updates or security advisories.

Long-Term Security Practices

Regularly update software and firmware to patch known vulnerabilities.
Implement the principle of least privilege to limit attack surfaces.

Patching and Updates

Keep the system updated with the latest security patches from the vendor.