CVE-2021-21124 : Exploit Details and Defense Strategies

This article provides details about CVE-2021-21124, a vulnerability in Google Chrome on Android that could allow a remote attacker to perform a sandbox escape via a crafted HTML page.

Understanding CVE-2021-21124

CVE-2021-21124 is classified as a potential user after free vulnerability in the Speech Recognizer component of Google Chrome on Android. This security flaw could be exploited by a remote attacker to potentially escape the browser's sandbox environment.

What is CVE-2021-21124?

The CVE-2021-21124 vulnerability involves a user after free issue in Google Chrome's Speech Recognizer on Android versions prior to 88.0.4324.96. This flaw could be abused by a malicious actor to execute arbitrary code and escape the browser's sandbox.

The Impact of CVE-2021-21124

The impact of CVE-2021-21124 is significant as it could lead to a sandbox escape in Google Chrome on Android devices. By exploiting this vulnerability, an attacker could potentially gain elevated privileges and execute malicious actions on the affected system.

Technical Details of CVE-2021-21124

The technical details of CVE-2021-21124 include:

Vulnerability Description

The vulnerability stems from a user after free issue in the Speech Recognizer component of Google Chrome on Android. This flaw allows an attacker to escape the browser's sandbox by executing crafted code through a malicious HTML page.

Affected Systems and Versions

Google Chrome versions prior to 88.0.4324.96 on Android are affected by CVE-2021-21124. Users using these versions are at risk of exploitation by remote attackers aiming to achieve a sandbox escape.

Exploitation Mechanism

To exploit CVE-2021-21124, an attacker needs to craft a malicious HTML page that triggers the user after free condition in the Speech Recognizer component of Google Chrome on vulnerable Android devices. By doing so, the attacker can execute arbitrary code and escape the browser's security restrictions.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-21124, consider the following security measures:

Immediate Steps to Take

Update Google Chrome on Android to version 88.0.4324.96 or newer to patch the vulnerability.
Avoid visiting untrusted websites or clicking on suspicious links that could lead to the execution of malicious code.

Long-Term Security Practices

Enable automatic updates for Google Chrome to ensure that you receive the latest security patches.
Regularly review security advisories and apply patches promptly to protect against known vulnerabilities.

Patching and Updates

Google has released an update addressing CVE-2021-21124 in Chrome version 88.0.4324.96. Users are advised to update their browsers immediately to safeguard against potential exploitation of this vulnerability.