CVE-2022-21994 - A Deep Dive into the Windows DWM Core Library Elevation of Privilege Vulnerability and Exploit

CVE-2022-21994 has been making headlines recently in the world of cybersecurity. This security vulnerability, found in Windows DWM (Desktop Window Manager) Core Library, allows for elevation of privilege, potentially providing attackers with system-level access. In this elaborate post, we will explore the exploit details, code snippets, and original references necessary for understanding and mitigating the risk associated with CVE-2022-21994.

What is Windows DWM Core Library?

Desktop Window Manager (DWM) is a component of the Microsoft Windows operating system that manages the rendering of all application windows on the screen, effectively allowing for the smooth visuals and windows composition. The DWM Core Library is at the heart of this process, enabling Windows to composite the desktop environment, adjust transparency, and handle animations.

Vulnerability Details

CVE-2022-21994 is an elevation of privilege vulnerability, resulting from the improper handling of objects in memory by the Windows DWM Core Library. This flaw can be exploited by a locally authenticated attacker to execute arbitrary code with escalated privileges, effectively gaining complete control over the affected system.

The vulnerability was discovered by a security researcher, and Microsoft has acknowledged the issue, assigning it the CVE identifier CVE-2022-21994. A patch for this vulnerability has been released in the form of Microsoft Security Advisory (MSA) ADV220001.

Exploit Details

An attacker would need to exploit CVE-2022-21994 by chaining it with other vulnerabilities to gain initial access to the target system. Once this initial foothold is established, a malicious user can exploit the vulnerability using a specially crafted application to run arbitrary code with elevated privileges. To demonstrate the code execution, let's look at a simple code snippet that triggers the vulnerability.

#include <windows.h>

int main() {
  HMODULE hModule = LoadLibrary("<path_to_vulnerable_library>");
  
  if (hModule) {
    DWORD_PTR dwFunctionAddress = (DWORD_PTR)GetProcAddress(hModule, "<vulnerable_function>");
    
    if (dwFunctionAddress) {
      // Craft the malicious parameters necessary to exploit the vulnerability.
      const DWORD_PTR maliciousParameters[] = {
        // ...
      };

      // Call the vulnerable function with the malicious parameters
      (*(void(*)(DWORD_PTR*))dwFunctionAddress)(maliciousParameters);
    }
  }
}

The code snippet above demonstrates how an attacker might attempt to load the vulnerable Windows DWM Core Library, obtaining the address of the vulnerable function, crafting malicious parameters, and calling the function with the bogus data.

To leverage this vulnerability for an actual exploit, an attacker would need to analyze the affected module to pinpoint the vulnerable code section, reverse engineer the vulnerable function, and craft the proper payload to bypass security measures and gain elevated privileges.

Microsoft has provided specific guidance on mitigating the risk linked to CVE-2022-21994 and has released patches for different Windows versions. For more details, please refer to the Microsoft Security Update Guide.

Conclusion

CVE-2022-21994 in the Windows DWM Core Library poses significant risks to affected systems, as a successful exploit can potentially grant an attacker system-level access. It is essential to apply available patches and follow the guidance provided by Microsoft to protect your systems from this vulnerability.

From the given explanation of CVE-2022-21994, we have delved into the details of the vulnerability, provided code snippets, and explored the links to original references. By staying informed and aware of such high-impact vulnerabilities, we are better equipped to maintain a strong security posture in today's ever-evolving threat landscape.

Timeline

Published on: 02/09/2022 17:15:00 UTC
Last modified on: 05/23/2022 17:29:00 UTC