CODEWITHSUNDEEP
c#.net-4.0wmi
bj0
bj0

Reputation: 8213

System.Management.ManagementException: "Privilege not held." When trying to Shutdown Windows 7 in C# 4.0 using WMI

I have a program with some legacy code that does the following to shutdown windows:

ManagementClass mc = new ManagementClass( "Win32_OperatingSystem" );

mc.Get();

mc.Scope.Options.EnablePrivileges = true;
ManagementBaseObject mboShutdown = mc.GetMethodParameters( "Win32Shutdown" );

mboShutdown["Flags"] = "5"; // shutdown + force
mboShutdown["Reserved"] = "0";

foreach( ManagementObject mbo in mc.GetInstances() )
{
    mbo.InvokeMethod( "Win32Shutdown", mboShutdown, null );
}

It was a .NET 3.5 application, and it was working without a problem. Recently, a dependency upgrade required bumping the target framework to 4.0 client profile. Now, whenever the code runs, I am getting the following exception:

System.Management.ManagementException: "Privilege not held."

The application is running under an Admin account on Windows 7, and nothing has changed other than updating this software.

The only information I have been able to find while searching for a solution was some very old bug reports about .NET 1.1, and the following thread on msdn that was never answered: http://social.msdn.microsoft.com/Forums/vstudio/en-US/fa0bcae5-6f30-42b6-bb5f-b8a6edb88ac4/encountered-privillege-not-held-exception-when-rebooting-the-server-in-net40-framewrk

Does anyone know what the cause of this issue is? Do I need to stop using WMI and just PInvoke InitiateSystemShutdownEx or something similar?

Upvotes: 2

Views: 3379

Answers (2)

Andrei Krasutski
Andrei Krasutski

Reputation: 5257

After you apply the April 2017 security updates described in Microsoft security update guidance CVE-2017-0160, the PowerShell v3.0+ stop-computer command fails. Additionally, if applications use power management methods, such as shutdown or reboot, from the Win32_OperatingSystem class and set the EnablePrivileges attribute to true, they may observe the same failure. A "Privilege not held" error message is returned.

Customer applications using power management methods, such as shutdown or reboot, from the Win32_OperatingSystem class and set the EnablePrivileges attribute to true, may observe the same “Privilege not held” error.

Example 2 (C# code) returns “Privilege not held” error:

[STAThread]
static void Main(string[] args)
{
    ManagementClass mgmtObject = new ManagementClass("Win32_OperatingSystem");
    foreach (ManagementObject iterMgmtObject in mgmtObject.GetInstances())
    {
        iterMgmtObject.Scope.Options.EnablePrivileges = true;
        iterMgmtObject.InvokeMethod("Reboot", null, null);
    }
}

To resolve this problem, install the update your system. More in the article.

Upvotes: 0

bj0
bj0

Reputation: 8213

Ok, so it probably has to do with SE_SHUTDOWN_NAME privilege. I'm not sure why it was working under .NET 3.5 and not .NET 4.0, but the following workaround works:

[StructLayout( LayoutKind.Sequential, Pack = 1 )]
internal struct TokPriv1Luid
{
    public int Count;
    public long Luid;
    public int Attr;
}

[DllImport( "kernel32.dll", ExactSpelling = true )]
internal static extern IntPtr GetCurrentProcess();

[DllImport( "advapi32.dll", ExactSpelling = true, SetLastError = true )]
internal static extern bool OpenProcessToken( IntPtr h, int acc, ref IntPtr phtok );

[DllImport( "advapi32.dll", SetLastError = true )]
internal static extern bool LookupPrivilegeValue( string host, string name, ref long pluid );

[DllImport( "advapi32.dll", ExactSpelling = true, SetLastError = true )]
internal static extern bool AdjustTokenPrivileges( IntPtr htok, bool disall, ref TokPriv1Luid newst, int len, IntPtr prev, IntPtr relen );

[DllImport( "user32.dll", ExactSpelling = true, SetLastError = true )]
internal static extern bool ExitWindowsEx( int flg, int rea );

public const int SE_PRIVILEGE_ENABLED = 0x00000002;
public const int TOKEN_QUERY = 0x00000008;
public const int TOKEN_ADJUST_PRIVILEGES = 0x00000020;
public const string SE_SHUTDOWN_NAME = "SeShutdownPrivilege";
public const int EWX_LOGOFF = 0x00000000;
public const int EWX_SHUTDOWN = 0x00000001;
public const int EWX_REBOOT = 0x00000002;
public const int EWX_FORCE = 0x00000004;
public const int EWX_POWEROFF = 0x00000008;
public const int EWX_FORCEIFHUNG = 0x00000010;


public static bool DoExitWin( int flg )
{
    TokPriv1Luid tp;
    var hproc = GetCurrentProcess();
    var htok = IntPtr.Zero;
    OpenProcessToken( hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref htok );
    tp.Count = 1;
    tp.Luid = 0;
    tp.Attr = SE_PRIVILEGE_ENABLED;
    LookupPrivilegeValue( null, SE_SHUTDOWN_NAME, ref tp.Luid );
    AdjustTokenPrivileges( htok, false, ref tp, 0, IntPtr.Zero, IntPtr.Zero );

    return ExitWindowsEx( flg, 0 );
}

I haven't tried, but my guess is that the WMI call might work after using the AdjustTokenPrivileges call as well.

Upvotes: 2

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