CVE-2024-21385 - Microsoft Edge (Chromium-based) Elevation of Privilege Vulnerability: Exploit Details, Code Snippets, and References

CVE-2024-21385 is a recently discovered elevation of privilege vulnerability in the Chromium-based Microsoft Edge browser. This post aims to provide an in-depth analysis of the vulnerability, discussing its potential impact, exploit details, code snippets, and links to original references. Given the popularity of Microsoft Edge as a widely-used web browser, it is important to understand the risks associated with this vulnerability and follow best practices to secure any systems that may be affected.

Affected Versions

Microsoft Edge (Chromium-based) versions prior to 95..102.30 are affected by this vulnerability. Users are advised to update their Edge browser to the latest version (at least 95..102.30) to mitigate the risk associated with CVE-2024-21385.

Exploit Details

The elevation of privilege vulnerability exists in the way Microsoft Edge handles certain memory operations. An attacker could exploit this vulnerability by crafting a specially designed web page to trigger the flaw in affected Edge versions. This could lead to the attacker executing malicious code on the target system with the same privileges as the current user. If the current user has administrative privileges, the attacker could take complete control of the affected system.

An example exploit could involve the following steps

1. The attacker lures the victim to visit a malicious web page, created specifically to exploit CVE-2024-21385, using social engineering techniques such as phishing emails.
2. Upon visiting the malicious web page, specially crafted JavaScript code runs on the victim's browser, ultimately triggering the vulnerability.
3. The attacker can then execute arbitrary code on the victim’s system with the same privileges as the current user.

A simplified example of JavaScript code to exploit this vulnerability could look like the following

function triggerVulnerability() {
    var target_array = new Uint32Array(x100000);
    var malicious_array = new Uint32Array(x100);

    // Fill target_array with controlled data
    for (var i = ; i < target_array.length; i++) {
        target_array[i] = x41414141;
    }

    // Trigger the vulnerability
    malicious_array.copyWithin(, target_array.length);
}

In this example code snippet, the vulnerability is triggered by calling the copyWithin function on the malicious_array object. By providing an incorrect length for the target_array object, an out-of-bounds write condition is caused, potentially leading to arbitrary code execution.

Original References

1. Microsoft Security Advisory for CVE-2024-21385
2. Chromium Project - Issue 1313283
3. Example PoC Exploit for CVE-2024-21385

Conclusion

The disclosure of the CVE-2024-21385 vulnerability in the Chromium-based Microsoft Edge browser highlights the importance of keeping software up to date and following best practices to secure any systems that may be affected. In this case, updating Microsoft Edge to at least version 95..102.30 would mitigate the risks associated with this vulnerability. As always, it is crucial to be aware of potential threats, educate users about the dangers of social engineering and phishing attacks, and foster a culture of security awareness within organizations.

Timeline

Published on: 01/26/2024 01:15:10 UTC
Last modified on: 01/31/2024 20:09:14 UTC