In the ever-evolving digital realm, we are continually confronted by security threats that challenge even the most robust defenses. In this post, we will analyze CVE-2022-23262, an Elevation of Privilege (EoP) vulnerability found in Microsoft Edge (Chromium-based). Specifically, this vulnerability affects Edge's Chromium rendering engine, which is responsible for rendering web content and interpreting JavaScript.

This EoP bug is different from CVE-2022-23263, even though both of them pertain to Microsoft Edge. Below, we delve into the technical details, explore the exploit, and provide references to relevant sources.

Background

CVE-2022-23262 highlights a serious security flaw that enables an attacker to elevate their privileges on the target system. This vulnerability is closely tied to the JavaScript engine used by Microsoft Edge's Chromium renderer. Upon exploiting the vulnerability, an attacker could gain unauthorized permissions and execute malicious operations within the system.

Exploit Details

The core of CVE-2022-23262 revolves around a 'use-after-free' vulnerability in Microsoft Edge's Chromium-based renderer. To understand this better, we need first to define what 'use-after-free' means.

In programming languages such as C or C++, wherein developers must handle memory allocation manually, a 'use-after-free' vulnerability occurs when a program continues to use a memory location even after the memory has been 'freed' or reclaimed. Consequently, it can lead to various security risks, including EoP.

Now that we have an understanding of 'use-after-free,' let us take a look at the code snippet that illustrates the root cause of this vulnerability:

// Simplified example to illustrate the vulnerability
function vulnerable_function() {
  let obj = new VulnerableObject();
  let reference = obj.vulnerable_property;

  // The 'free' operation is invoked for 'obj'
  obj.free();

  // 'reference' is still pointing to the 'vulnerable_property'
  reference.perform_operation();
}

In this simplified example, we can see that the vulnerable_function creates an instance of VulnerableObject and takes a reference to its vulnerable property. After that, the free method gets invoked, which deallocates the memory associated with the object. However, the reference still refers to the vulnerable property after the object's memory has been freed. Finally, the perform_operation function is accessed through the reference, resulting in a 'use-after-free' situation.

An attacker could exploit this vulnerability by crafting a malicious web page and luring the victim into visiting it. Once the victim's Microsoft Edge browser with a vulnerable version of the Chromium renderer loads the page, the attacker's JavaScript code triggers the 'use-after-free' vulnerability, elevates privileges, and executes unauthorized actions on the target system.

Mitigation

Microsoft has addressed this vulnerability in its security updates. Users are advised to install the latest version of Microsoft Edge to protect their systems from this EoP vulnerability.

For additional information about this vulnerability, consult the following resources

1. Original CVE report: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23262
2. Microsoft's official security advisory: https://msrc.microsoft.com/update-guide/en-us/vulnerability/CVE-2022-23262

Conclusion

Security vulnerabilities such as CVE-2022-23262 are a vivid reminder of the challenges we face in the digital world. By understanding the root cause and learning how to exploit such vulnerabilities, we can better prepare and defend our systems from potential threats. Be sure to keep your software up-to-date and stay informed about the latest security vulnerabilities to proactively safeguard your digital environment.

Timeline

Published on: 02/07/2022 17:15:00 UTC
Last modified on: 02/12/2022 01:29:00 UTC