CVE-2024-21508 is a critical remote code execution (RCE) vulnerability that affects the popular MySQL2 package in versions prior to 3.9.4. This post is a deep dive into the inner workings of this vulnerability and provides details on how an attacker could exploit it to execute arbitrary code on the targeted system. We will also discuss the mitigating factors, potential remediations, and best practices to help protect your application from CVE-2024-21508.

Background

MySQL2 is a widely used Node.js driver for MySQL, designed to offer better support for the MySQL protocol than the default Node.js driver. The package is known for its performance benefits, reliability, and ease of use. Unfortunately, versions of the package prior to 3.9.4 contain a vulnerability that allows for the execution of arbitrary code remotely.

Vulnerability Details

The vulnerability (CVE-2024-21508) stems from the readCodeFor function, which is responsible for parsing and validating the user-provided supportBigNumbers and bigNumberStrings values. Unfortunately, prior to version 3.9.4, the package failed to properly validate these values, leading to the possibility of remote code execution.

The vulnerable code snippet from the readCodeFor function looks like this

function readCodeFor(options) {
  let supportBigNumbers = options.supportBigNumbers || false;
  let bigNumberStrings = options.bigNumberStrings || false;
  ...
}

Attack Scenario

An attacker could exploit CVE-2024-21508 by crafting a malicious payload that manipulates the supportBigNumbers and bigNumberStrings values, leading to the execution of arbitrary code on the target system. The crafted payload could look something like this:

{
  "supportBigNumbers": "function() { return /* malicious code */; }",
  "bigNumberStrings": "function() { return /* malicious code */; }"
}

When the vulnerable readCodeFor function processes this payload, it would execute the malicious code, potentially leading to a full system compromise.

Mitigating Factors

While the impact of CVE-2024-21508 is severe, its exploitation requires an attacker to have the ability to control the supportBigNumbers and bigNumberStrings values. This means that applications that properly validate user input and do not allow for the manipulation of these values are less likely to be affected by this vulnerability.

Remediation

The best way to remediate CVE-2024-21508 is to update the affected MySQL2 package to version 3.9.4 or later. This can be done by running the following command:

npm install mysql2@latest

If updating to version 3.9.4 or later is not possible, it's essential to ensure that user input is thoroughly validated and that supportBigNumbers and bigNumberStrings values are not manipulated by untrusted sources.

Best Practices

To protect your application against similar vulnerabilities in the future, consider adopting the following best practices:

1. Keep all dependencies, including the MySQL2 package, up to date to ensure that you always have the latest security patches.

Never trust user input and always validate and sanitize it before processing.

3. Adopt a strong and consistent input validation strategy, including the use of well-tested libraries and patterns.
4. Stay informed about known security vulnerabilities in the packages you use and the technologies you rely on.

Conclusion

CVE-2024-21508 is a severe remote code execution vulnerability in the MySQL2 package that affects versions prior to 3.9.4. By updating your package to the latest version, validating user input, and adopting other best practices, you can protect your application from exploitation of this and similar vulnerabilities.

Original References

- MySQL2 GitHub Repository
- Official CVE Details - CVE-2024-21508
- NIST National Vulnerability Database - CVE-2024-21508
- MySQL2 Changelog

Timeline

Published on: 04/11/2024 05:15:47 UTC
Last modified on: 06/18/2024 20:18:04 UTC