CVE-2021-33443 : Security Advisory and Response

A stack buffer overflow vulnerability was discovered in mjs (mJS: Restricted JavaScript engine), ES6 (JavaScript version 6), specifically in the mjs_execute() function in mjs.c.

Understanding CVE-2021-33443

This CVE involves a critical stack buffer overflow vulnerability in the mJS JavaScript engine, which could be exploited by attackers to execute malicious code.

What is CVE-2021-33443?

CVE-2021-33443 is a security vulnerability in the mJS JavaScript engine, allowing an attacker to trigger a stack buffer overflow through the mjs_execute() function.

The Impact of CVE-2021-33443

This vulnerability could lead to remote code execution, denial of service, or potentially even full control over the affected system by malicious actors.

Technical Details of CVE-2021-33443

The following technical details outline the specifics of the vulnerability:

Vulnerability Description

The vulnerability exists due to a lack of proper validation of user-supplied input in the mjs_execute() function.

Affected Systems and Versions

All versions of mJS (mJS: Restricted JavaScript engine) utilizing ES6 (JavaScript version 6) are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting a specially designed input to trigger a stack buffer overflow and potentially execute arbitrary code.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-33443, the following steps should be taken:

Immediate Steps to Take

Implement a temporary workaround by restricting access to vulnerable components.
Monitor for any suspicious activities or unexpected behavior on the system.

Long-Term Security Practices

Regularly update the mJS JavaScript engine to the latest version to patch known vulnerabilities.
Conduct security assessments to identify and address any underlying security weaknesses.

Patching and Updates

Keep abreast of security advisories and promptly apply patches released by the mJS maintainers to address the vulnerability.