In the ever-evolving landscape of cybersecurity, vulnerabilities in various systems are discovered and exploited regularly. One such vulnerability, dubbed CVE-2023-36803, affects the Windows Kernel. This information disclosure vulnerability is a critical issue that exposes sensitive information in the system memory. In this post, we will delve deep into this vulnerability, discussing what it is, how it can be exploited, and some possible mitigations to reduce the risks it poses.


CVE-2023-36803 is an information disclosure vulnerability that affects certain versions of the Windows operating system kernel. The Windows Kernel is the core part of the operating system responsible for managing essential system resources such as memory, processes, and hardware.

An attacker who successfully exploits this vulnerability can gain access to sensitive information in the system memory. This information could be used to craft further attacks that may lead to a complete compromise of the affected system. You can refer to the official Microsoft Security Advisory MSA-2023-XX for more information on the affected versions of Windows and the severity of the vulnerability.

Exploitation Details

The vulnerability lies in the way the Windows Kernel handles certain memory allocations for user-mode applications. When an application requests memory to be allocated, the kernel should ensure that the memory region is properly initialized before it is assigned to the process.

However, due to an insufficient initialization issue within the kernel, an attacker can request memory allocation and gain access to uninitialized memory containing sensitive information. This sensitive information could include encryption keys, passwords, or other sensitive data related to the system or user.

Consider the following code snippet that demonstrates the exploitation of CVE-2023-36803

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

int main()
    PVOID pAddress = NULL;
    SIZE_T size = x100;
    // Allocate a memory region
    if (NtAllocateVirtualMemory(NtCurrentProcess(),
                                 PAGE_READWRITE) == STATUS_SUCCESS)
        // Read the uninitialized memory
        for (size_t i = ; i < size; i += sizeof(DWORD))
            DWORD value = *(PDWORD)((PUCHAR)pAddress + i);
            printf("Uninitialized data at %p: x%08X\n", (PUCHAR)pAddress + i, value);
        printf("Memory allocation failed.\n");
    return ;

This simple program allocates memory and immediately reads the contents of the uninitialized memory, disclosing the potentially sensitive information.

Possible Mitigations

Mitigations for this vulnerability can be applied at both the software and user levels. From a software perspective, Microsoft has released patches for the affected operating systems. It is highly recommended that you update your systems to the latest version that includes these patches. To learn more about these updates and how to apply them, visit the following link:

- Microsoft Security Update Guide

As a user, it is crucial to adopt safe computing practices to minimize the risk of exploitation. This includes regularly updating and patching your systems, using strong anti-malware software, and being cautious when interacting with unfamiliar applications or sources.


CVE-2023-36803 is a serious vulnerability within the Windows Kernel that exposes sensitive information in system memory. By understanding its implications and taking appropriate steps to mitigate the risks it poses, we can better protect ourselves and our systems from potential exploits. Regularly updating your systems, being aware of emerging vulnerabilities, and implementing safe computing practices can all contribute to a more secure environment.


Published on: 09/12/2023 17:15:00 UTC
Last modified on: 09/12/2023 19:38:00 UTC