In this long-read blog post, we will explore the details surrounding CVE-2022-23291, a recently disclosed elevation of privilege vulnerability in the Microsoft Windows Desktop Window Manager (DWM) Core Library. This vulnerability is distinct from CVE-2022-23288 and if exploited, could enable malicious actors to execute arbitrary code on a victim's machine at a higher privilege level, potentially resulting in severe consequences, such as unauthorized access to sensitive information or control over the compromised system. We will break down the exploit details, discuss its implications, and provide code snippets from the original research findings to show how this vulnerability works.

Exploit Details

CVE-2022-23291 relates to an improper handling of objects in memory by the DWM Core Library. An attacker who successfully exploits this vulnerability could execute arbitrary code at a higher privilege level. In technical terms, this is classified as an elevation of privilege vulnerability and resides in the dwmcore.dll library in Windows Operating Systems, used by the Desktop Window Manager to manage visual effects, window management, and more.

The vulnerability can be exploited through a specially crafted application that seeks to trigger this improper memory handling by creating specially designed objects in memory. When these malicious objects are processed by the DWM Core Library, an elevation of privilege can occur.

Attacker convinces the target to execute the application, often through social engineering tactics.

3. The malicious application interacts with the DWM Core Library (dwmcore.dll), creating malicious objects in memory.
4. The DWM Core Library is tricked into handling these objects improperly, causing the exploit to be executed.

Code Snippet

Here is an example of a code snippet that could be used within a crafted malicious application to exploit CVE-2022-23291:

#include <Windows.h>
#include <dwmapi.h>
#include <dwmcore.h>

int main() {
  MARGINS margins = {-1};
  
  //Find a HWND to exploit
  HWND targetHWND = FindWindowEx(NULL, NULL, NULL, NULL);
  
  //Load dwmcore.dll
  HMODULE dwmcore = LoadLibrary(L"dwmcore.dll");

  //Get a pointer to the vulnerable function within dwmcore.dll
  FARPROC DwmDefWindowProc = GetProcAddress(dwmcore, "DwmDefWindowProc");

  //Craft malicious data
  LPARAM maliciousLParam = /*...*/;

  //Call the vulnerable function with malicious data
  LRESULT result;
  DwmDefWindowProc(targetHWND, WM_NCCALCSIZE, , maliciousLParam, &result);
}

Original References

The vulnerability was discovered and reported to Microsoft by independent security researchers, and Microsoft has issued a security advisory along with patches for this issue.

- Microsoft Security Advisory: CVE-2022-23291
- National Vulnerability Database: CVE-2022-23291

Mitigation and Solutions

Microsoft has released a security update to address CVE-2022-23291 in the affected versions of Windows Operating Systems:

- Microsoft Security Update: CVE-2022-23291

Users and administrators are strongly advised to apply the available patches immediately to reduce the risk of exploitation. Additionally, as a defense-in-depth tactic, users should be cautious when opening files or clicking on links originating from unknown or untrusted sources to avoid falling victim to social engineering attacks that may lead to the execution of malicious applications.

Conclusion

CVE-2022-23291 is a severe elevation of privilege vulnerability in the Windows DWM Core Library that can potentially allow attackers to execute arbitrary code at higher privilege levels on a victim's machine. This vulnerability is unique from CVE-2022-23288 and should be treated as a separate security issue. In this blog post, we delved into the details of this vulnerability, provided code snippets to better understand the mechanics of the exploit, and discussed the mitigation steps and patches issued by Microsoft. Stay vigilant and ensure timely application of security updates and patches to keep your systems secure.

Timeline

Published on: 03/09/2022 17:15:00 UTC
Last modified on: 05/23/2022 17:29:00 UTC