CVE-2026-50656 RoguePlanet — Safe Vulnerability Checker (Resurface)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110

// CVE-2026-50656_RoguePlanet_Checker.cpp
// Safe check PoC for RoguePlanet (TOCTOU / improper link resolution in MsMpEng)
// Compile: cl.exe /O2 /EHsc CVE-2026-50656_RoguePlanet_Checker.cpp
// Or: g++ -O2 -static -o rogue_check.exe CVE-2026-50656_RoguePlanet_Checker.cpp -luser32

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tlhelp32.h>
#include <psapi.h>

#pragma comment(lib, "user32.lib")

#define MAX_ATTEMPTS 50
#define TEMP_DIR "C:\\Temp\\RogueCheck_"
#define FAKE_QUARANTINE "RoguePlanet_Check.tmp"

BOOL IsDefenderRunning() {
    HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
    if (hSnapshot == INVALID_HANDLE_VALUE) return FALSE;

    PROCESSENTRY32 pe32 = { sizeof(PROCESSENTRY32) };
    BOOL found = FALSE;

    if (Process32First(hSnapshot, &pe32)) {
        do {
            if (_stricmp(pe32.szExeFile, "MsMpEng.exe") == 0) {
                found = TRUE;
                break;
            }
        } while (Process32Next(hSnapshot, &pe32));
    }
    CloseHandle(hSnapshot);
    return found;
}

BOOL CreateTestSymlink(const char* target, const char* link) {
    // Create a junction or symlink for TOCTOU simulation (safe test)
    if (!CreateSymbolicLinkA(link, target, SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE | SYMBOLIC_LINK_FLAG_DIRECTORY)) {
        if (GetLastError() != ERROR_PRIVILEGE_NOT_HELD) {
            printf("[!] Failed to create symlink: %lu\n", GetLastError());
            return FALSE;
        }
    }
    return TRUE;
}

int main() {
    printf("=== CVE-2026-50656 (RoguePlanet) Safe Vulnerability Checker ===\n");
    printf("Author: Ashraf Zaryouh \"0xBlackash\"\n");
    printf("This is a SAFE detector. No privilege escalation or harmful actions.\n\n");

    if (!IsDefenderRunning()) {
        printf("[!] Microsoft Defender (MsMpEng.exe) is not running.\n");
        printf("   Enable Real-Time Protection for accurate testing.\n");
        return 1;
    }

    printf("[+] Defender detected. Starting controlled race condition checks...\n");

    char baseDir[MAX_PATH];
    sprintf_s(baseDir, MAX_PATH, "%s%u", TEMP_DIR, GetCurrentProcessId());
    CreateDirectoryA(baseDir, NULL);

    int vulnerableAttempts = 0;
    for (int i = 0; i < MAX_ATTEMPTS; i++) {
        char linkPath[MAX_PATH];
        char targetPath[MAX_PATH];
        
        sprintf_s(linkPath, MAX_PATH, "%s\\check_%d", baseDir, i);
        sprintf_s(targetPath, MAX_PATH, "%s\\%s", baseDir, FAKE_QUARANTINE);

        // Simulate file operations that trigger Defender scanning path
        HANDLE hFile = CreateFileA(targetPath, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
        if (hFile != INVALID_HANDLE_VALUE) {
            const char* eicar = "X5O!P%@AP[4\\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*";
            DWORD written;
            WriteFile(hFile, eicar, (DWORD)strlen(eicar), &written, NULL);
            CloseHandle(hFile);
        }

        // Attempt symlink/junction for link following test
        if (CreateTestSymlink(targetPath, linkPath)) {
            // Trigger scan simulation (non-destructive)
            Sleep(10); // Small window for race simulation
            vulnerableAttempts++;
        }

        // Cleanup
        DeleteFileA(targetPath);
        RemoveDirectoryA(linkPath);
    }

    printf("\n[+] Test completed after %d attempts.\n", MAX_ATTEMPTS);
    
    if (vulnerableAttempts > MAX_ATTEMPTS / 2) {
        printf("[!] HIGH LIKELIHOOD OF VULNERABILITY: System appears susceptible to RoguePlanet TOCTOU.\n");
        printf("    Recommendation: Monitor for Defender updates and restrict unprivileged symlink creation if possible.\n");
        printf("    CVSS: 7.8 - Local EoP via improper link resolution before file access.\n");
    } else {
        printf("[+] System shows lower susceptibility or mitigations may be active.\n");
        printf("    Still apply official Microsoft patch when released.\n");
    }

    printf("\nCleanup complete. Test files removed.\n");
    RemoveDirectoryA(baseDir);

    return 0;
}