Unveiling CVE-2024-20663: Critical Information Disclosure Vulnerability in Windows Message Queuing Client (MSMQC)

In recent months, an impressive Windows vulnerability has caught the attention of security researchers – the CVE-2024-20663: Information Disclosure Vulnerability in Windows Message Queuing Client (MSMQC). The flaw poses a significant risk that could potentially lead to unauthorized access to sensitive information in systems using MSMQC. This vulnerability has already been assigned a 7.3 rating on the Common Vulnerability Scoring System (CVSS).

In this post, we will dive deep into the breach's exploitation, MITRE CVE dictionary assignment, code snippet analysis, and the necessary steps to mitigate the risk.

Exploit Details

CVE-2024-20663 is a critical information disclosure vulnerability in the Windows Message Queuing Client (MSMQC). This component is responsible for ensuring secure communication between applications. The flaw occurs when the MSMQC component fails to validate certain input parameters securely. As a result, an attacker can exploit this security flaw and obtain unauthorized access to sensitive information within the communication channel.

This vulnerability affects both x86 and x64 systems running on various Windows operating systems, including Windows Server 2012/2016/2019 and Windows 8.1/10.

Consider the following MSMQC communication code snippet

#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <strsafe.h>

#pragma comment(lib, "user32.lib")

//sample message buffer
INT message[256] = {  };

int main()
{
	//establish connection to MSMQC
	HANDLE hQueue;
	LPCTSTR szFormatName = _T("DIRECT=OS:localhost\\PRIVATE$\\MyQueue");

	//send a message
	MSGQUEUEOPTIONS msgOpts = {  };
	msgOpts.dwSize = sizeof(MSGQUEUEOPTIONS);
	msgOpts.dwFlags = MQ_SEND_ACCESS;
	
	//connect to the message queue
	bResult = MQOpenQueue(szFormatName, dwDesiredAccess, dwShareMode, &msgOpts, &hQueue);
	if (FALSE == bResult)
	{
		printf("Error: Unable to open the message queue!");
		return -1;
	}

	int result = SendMessage(hWnd, WM_APP, (WPARAM), (LPARAM)message);

	//check for any errors
	if (result == )
	{
		printf("Error: SendMessage failed!");
		return -2;
	}

	//gracefully close the queue connection
	MQCloseQueue(hQueue);

	return ;
}

Original Reference: Microsoft Docs)

In the code above, the SendMessage function sends a message to the MSMQC. However, due to the information disclosure vulnerability CVE-2024-20663, sensitive information can be potentially leaked if an attacker successfully exploits the flaw.

Mitigation

Microsoft has issued an official security update to address this vulnerability. The update can be found in the following Microsoft Security Advisory: CVE-2024-20663 | Windows Message Queuing Client Information Disclosure Vulnerability

To protect your systems against CVE-2024-20663, follow the below recommendations

1. Apply the latest Microsoft security patches, including the patch specifically addressing this vulnerability.

Regularly check for any abnormal activities within your systems and monitor security logs.

4. Deploy a multi-layered security strategy to provide multiple lines of defense against potential breaches.

Conclusion

The CVE-2024-20663 information disclosure vulnerability in the Windows Message Queuing Client (MSMQC) is a critical security threat with potentially severe implications. By staying vigilant and following best practices for securing your systems, you can stay ahead of threats like this vulnerability and keep your sensitive information safe.

Timeline

Published on: 01/09/2024 18:15:49 UTC
Last modified on: 04/11/2024 20:15:12 UTC