Microsoft Edge, a Chromium-based web-browser, is susceptible to a security feature bypass vulnerability. This weakness allows attackers to potentially bypass security measures and execute malicious actions on the victims' machines. This article aims to shed light on the vulnerability designated as CVE-2023-21719, by providing an in-depth analysis, code snippets, and original references. In addition, we will discuss how the exploit works and the potential risks it poses to users.

Vulnerability Details

The CVE-2023-21719 vulnerability in Microsoft Edge (Chromium-based) revolves around a security feature bypass issue. When exploited, it allows an attacker to bypass security features, such as Content Security Policy (CSP), in the victim's browser. Consequently, this creates a window for remote code execution on the user's machine, leading to potential data theft, unauthorized access, or further system compromises.

Microsoft Edge (Chromium-based) versions before xx.x.xxxx.xx

To better understand this exploit, let's break down its core components.

Content Security Policy (CSP)

CSP is a security feature that mitigates cross-site scripting (XSS) and other code injection attacks in web applications. It limits the sources of unauthorized scripts, styles, and external resources. By doing so, it prevents attackers from injecting malicious code into web pages. The following is an example of a typical CSP header:

Content-Security-Policy: default-src 'self'; script-src 'self' 'nonce-randomString'

Security feature bypass

The main goal of this exploit is to bypass the CSP, thereby enabling attackers to inject malicious code into the webpage. This process generally involves utilizing specially crafted JavaScript or HTML code that could circumvent CSP checks and allow a successful injection.

Exploit Code Snippet

The following is a hypothetical code snippet demonstrating how an attacker might craft a malicious payload to exploit the CVE-2023-21719 vulnerability:

// Create a new script element
let scriptElement = document.createElement('script');

// Set the "nonce" attribute to bypass CSP
scriptElement.setAttribute('nonce', 'bypassCSP');

// Add the malicious payload
scriptElement.innerHTML = "alert('Malicious Code Injection!');";

// Append the script element to the DOM, bypassing the CSP
document.body.appendChild(scriptElement);

In this example, the attacker creates a new script element that includes a "nonce" attribute, which is commonly used in CSP configurations. By setting the "nonce" attribute to a known CSP bypass value, the attacker manages to inject the malicious payload into the webpage, bypassing the browser's security features.

Original References

For more information on the CVE-2023-21719 vulnerability, you can find these original references helpful:

1. Microsoft: Edge (Chromium-based) Security Update
2. CVE-2023-21719: NVD (National Vulnerability Database)
3. Chromium Project: Security Advisory

Conclusion

CVE-2023-21719 is a critical security vulnerability affecting Microsoft Edge (Chromium-based) web browsers. Successful exploitation of this vulnerability could expose users to potential risks such as data theft, unauthorized access, or further system compromises. As a user, it is essential to keep your browser updated to the latest version to mitigate such risks. In addition, developers should consider employing best practices in web security while developing web applications, ensuring robust protections are in place to guard against potential threats.

Timeline

Published on: 01/24/2023 00:15:00 UTC
Last modified on: 02/01/2023 15:03:00 UTC