Avviso di sicurezza Microsoft: una vulnerabilità relativa a SQL Server potrebbe causare l'esecuzione di codice in modalità remota

'*************************************************************************************
'Descrizione: Questo script effettua iterazioni tra tutte le istanze in esecuzione di SQL Server
'            e nega le autorizzazioni di esecuzione in sp_replwritetovarbin al pubblico su tutte
'            le versioni interessate.
'             LO SCRIPT VIENE FORNITO COME SOLUZIONE E NON DEVE ESSERE UTILIZZATO NEL CASO IN CUI
'            VENGA FORNITO E INSTALLATO UN AGGIORNAMENTO DELLA PROTEZIONE.
'*************************************************************************************

OPTION EXPLICIT
ON ERROR RESUME NEXT

' Valori costanti
CONST EXIT_SUCCESS       = 0
CONST EXIT_FAILURE       = 1
CONST EXIT_NOINSTANCES   = -1
CONST DEFAULTNAMESPACE   = "root\default"
CONST STDREGPROV         = "stdregprov"
CONST HKEY_LOCAL_MACHINE = &H80000002
CONST REG_MULTI_SZ       = 7
CONST REG_SZ             = 1
CONST adCmdText          = 1


Call VBMain()

Function VBMain()
    Err.Clear
    ON ERROR RESUME NEXT

    Dim sInstances(), strInstance, i, TotalCount
    VBMain = EXIT_SUCCESS
    If GetInstances(sInstances, TotalCount) = FALSE Then
        WScript.Quit EXIT_FAILURE
    End If

    If IsEmptyNull(sInstances) Then 
        WScript.Echo "INFO: Nessuna istanza presente."
        VBMain = EXIT_NOINSTANCES
        Exit Function
    End If

    For i = 0 To TotalCount-1
        strInstance = sInstances(i,0)
        GetFullInstance strInstance, sInstances(i,1)
        If ApplyFix(sInstances(i,0), strInstance) = FALSE Then
            WScript.Echo "ERROR: Impossibile applicare la soluzione a " + sInstances(i,0) + "." + vbCRLF
            VBMain = EXIT_FAILURE
        End If
    Next

    WScript.Echo "INFO: Elaborazione delle istanze in esecuzione di SQL completata."
End Function

Function GetInstances(ByRef sInstances, ByRef TotalCount)
    Err.Clear
    ON ERROR RESUME NEXT

    Dim sInstances1, sInstances2, i
    Dim instCount1, instCount2
    GetInstances = FALSE

    If NOT GetRegValue ("", HKEY_LOCAL_MACHINE, "Software\Microsoft\Microsoft SQL Server", "InstalledInstances", sInstances1, REG_MULTI_SZ, TRUE) Then
        WScript.Echo "ERROR: impossibile leggere le istanze SQL installate sul computer."
        Exit Function
    End If

    sInstances2 = NULL
    If IsOs64Bit() = TRUE Then
        If NOT GetRegValue ("", HKEY_LOCAL_MACHINE, "Software\Microsoft\Microsoft SQL Server", "InstalledInstances", sInstances2, REG_MULTI_SZ, FALSE) Then
            WScript.Echo "ERROR: impossibile leggere le istanze SQL installate sul computer."
            Exit Function
        End If
    End If

    If IsEmptyNull(sInstances1) AND IsEmptyNull(sInstances2) Then 
        WScript.Echo "INFO: Nessuna istanza presente."
        WScript.Quit EXIT_SUCCESS
    End If

    instCount1 = 0
    instCount2 = 0 
    TotalCount = 0
    If IsEmptyNull(sInstances1) = FALSE Then
        instCount1 = UBound(sInstances1) + 1
        TotalCount = instCount1
    End If

    If IsEmptyNull(sInstances2) = FALSE Then
        instCount2 = UBound(sInstances2) + 1
        TotalCount = TotalCount + instCount2
    End If

    ReDim PRESERVE sInstances(TotalCount,1)
    if instCount1 > 0 Then
        For i = 0 To UBound(sInstances1)
            sInstances(i,0) = sInstances1(i)
            sInstances(i,1) = True
        Next
    End If
    If instCount2 >0 Then
        For i = 0 To UBound(sInstances2)
            sInstances(i+instCount1,0) = sInstances2(i)
            sInstances(i+instCount1,1) = FALSE
        Next
    End If
    GetInstances = TRUE
End Function


Function ApplyFix(ByVal strInstance, ByVal strServerName)
    Err.Clear
    ON ERROR RESUME NEXT

    Dim objConn, objCmd, objCmd1, objRS, objRS1
    Dim strCommand, strConn
    Dim strBuildVersion, strProductLevel, bApplyFix

    ' Initialize return value
    ApplyFix = FALSE

    strConn = "Provider=sqloledb;Initial Catalog=master;Integrated Security=SSPI;Data Source=" + strServerName + ";"
    ' La verifica degli errori è stata abbandonata intenzionalmente per non modificare la lunghezza del codice
    Set objConn = CreateObject("ADODB.Connection")
    Set objCmd = CreateObject("ADODB.Command")
    Set objCmd1 = CreateObject("ADODB.Command")

    ' Avviare una connessione con il database master
    objConn.Open strConn 
    If ErrorOccurred("Error: Impossibile connettersi a " + strInstance) Then
        Set objConn = Nothing
        Exit Function
    End If

    ' Convalidare la versione prima di applicare la correzione
    strCommand = "select SERVERPROPERTY('ProductVersion') as version, SERVERPROPERTY('productlevel') as productlevel"
    objCmd.ActiveConnection = objConn
    objCmd.CommandType = adCmdText
    objCmd.CommandText = strCommand

    Set objRS = objCmd.Execute()
    If ErrorOccurred("ERROR: Impossibile eseguire """ + strCommand + """ on " + strInstance) = TRUE Then
        objConn.Close()
        Set objConn = Nothing
        ApplyFix = FALSE
        Exit Function   
    End If

    strBuildVersion = objRS("versione")
    strProductLevel = UCase(objRS("productlevel"))

    bApplyFix = FALSE
    ' Applicare la soluzione solamente per le versioni SQL 2000 e SQL 2005 (RTM, SP1 e SP2)
    If (CInt(Mid(strBuildVersion,1,1)) = 8) Then
        bApplyFix = TRUE
    ElseIf CInt(Mid(strBuildVersion,1,1)) = 9 AND (StrComp(strProductLevel,"RTM") = 0 OR StrComp(strProductLevel,"SP1") = 0 OR StrComp(strProductLevel,"SP2") = 0) Then
        bApplyFix = TRUE
    End If 

    If bApplyFix = TRUE Then
        strCommand = "deny execute on sp_replwritetovarbin to public"
        objCmd1.ActiveConnection = objConn
        objCmd1.CommandType = adCmdText
        objCmd1.CommandText = strCommand
        Set objRS1 = objCmd1.Execute()
        If ErrorOccurred("ERROR: Impossibile eseguire """ + strCommand + """ on " + strInstance) = FALSE Then
            WScript.Echo "INFO: Soluzione applicata correttamente a " + strInstance + " (" + strBuildVersion + ")." + vbCRLF
            ApplyFix = TRUE
        End If
    Else
        WScript.Echo "INFO: Ignorare la raccolta di informazioni per " + strInstance + " (" + strBuildVersion + ") in quanto l'istanza non è vulnerabile." + vbCRLF
        ApplyFix = TRUE
    End If

    objConn.Close()
    Set objConn = Nothing
    Set objCmd = Nothing
    Set objCmd1 = Nothing
    Set objRS = Nothing
    Set objRS1 = Nothing
End Function

Private Function GetRegValue (ByVal strMachineName, ByVal hMainKey, ByVal strPath, ByVal strValueName, ByRef strValue, ByVal iValueType, ByVal b32bit)
    Err.Clear
    ON ERROR RESUME NEXT

    Dim objLocator, objServices, objRegistry, objCtx
    Dim sMultiStrings, lRc
    GetRegValue = TRUE

    'Connect to WMI and get an object to STDREGPROV class.
    Set objCtx = CreateObject("WbemScripting.SWbemNamedValueSet")
    If b32bit = TRUE Then
        objCtx.Add "__ProviderArchitecture", 32
    Else
        objCtx.Add "__ProviderArchitecture", 64
    End If
    objCtx.Add "__RequiredArchitecture", TRUE
    set objLocator = createobject("wbemscripting.swbemlocator")
    set objServices = objLocator.connectserver(strMachineName,DEFAULTNAMESPACE, "", "",,,,objCtx)
    set objRegistry = objServices.get(STDREGPROV)
    If ErrorOccurred("ERROR: Impossibile connettersi allo spazio dei nomi WMI " + DEFAULTNAMESPACE) Then
        GetRegValue = FALSE
        Exit Function
    End If 

    lRc = 0
    Select Case iValueType
        ' We only care about REG_MULTI_SZ
        Case REG_MULTI_SZ
            strValue = ""
            lRC = objRegistry.GetMultiStringValue(hMainKey, strPath, strValueName, sMultiStrings)
            strValue = sMultiStrings
        Case REG_SZ
            strValue = ""
            lRC = objRegistry.GetStringValue(hMainKey, strPath, strValueName, strValue)
        Case Else
            GetRegValue = FALSE
    End Select

    If lRc = 2 Or lRc = 3 Then
        GetRegValue = TRUE
        strValue = ""
    ElseIf Err.Number OR lRc <> 0 Then
        GetRegValue = FALSE
    End If

    Set MAPIMessage = Nothing
    Set objServices = Nothing
    Set MAPIMessage = Nothing
End Function

Function IsEmptyNull(sCheck)
    IsEmptyNull = FALSE
    If IsObject(sCheck) Then Exit Function
    If IsObject(sCheck) Then Exit Function
    If VarType(sCheck) = vbEmpty Then IsEmptyNull = TRUE : Exit Function
    If VarType(sCheck) = vbEmpty Then IsEmptyNull = TRUE : Exit Function
    If sCheck = "" Then IsEmptyNull = TRUE
End Function

Private Function ErrorOccurred (ByVal strIn)
    If Err.Number <> 0 Then
        WScript.Echo strIn
        WScript.Echo "ERROR: 0x" & Err.Number & " - " & Err.Description
        Err.Clear
        ErrorOccurred = TRUE
    Else
        ErrorOccurred = FALSE
    End If
End Function

Function IsOs64Bit()
    Err.Clear
    ON ERROR RESUME NEXT

    Dim objProc
    Set objProc = GetObject("winmgmts:root\cimv2:Win32_Processor='cpu0'")
    If objProc.Architecture = 0 Then
        IsOs64Bit = FALSE
    Else
        IsOs64Bit = TRUE
    End If
End Function

Function GetFullInstance (ByRef strInstanceName, ByVal b32bit)
    Err.Clear
    ON ERROR RESUME NEXT 

    Dim objServices, objClusters, objCluster
    Dim strMacName, isEmpty
    Dim strKey, strInstID

    GetFullInstance = TRUE

    If strComp(UCase(strInstanceName), "MICROSOFT##SSEE", 1) = 0 Then
        strInstanceName = "np:\\.\pipe\mssql$microsoft##ssee\sql\query"
        Exit Function
    End if

    strMacName = ""
    Set objServices = GetObject("winmgmts:root\cimv2")

    ' Query Cluster service
    Set objClusters = objServices.ExecQuery ("select * from win32_service where Name='ClusSvc' AND Started = TRUE")
    isEmpty = TRUE
    If Err.Number = 0 Then
        For each objCluster in objClusters
            isEmpty = FALSE
        Next
    End If

    Set objServices = Nothing
    Set objClusters = Nothing

    If isEmpty = TRUE Then
        strInstanceName = BuildInstanceName (".", strInstanceName)
        Exit Function
    End If

    ' Il raggiungimento di questa posizione indica che il computer è un nodo cluster.
    ' Effettuare query del Registro di sistema per determinare se l'istanza SQL sia di tipo cluster.
    ' Per la query SQL 2000 il seguente valore
    ' HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\<InstanceName>\Cluster
    ' ClusterName
    strKey = "SOFTWARE\Microsoft\Microsoft SQL Server\" + strInstanceName + "\Cluster"
    GetRegValue "", HKEY_LOCAL_MACHINE, strKey, "ClusterName", strMacName, REG_SZ, b32bit

    If StrComp(strMacName, "") <> 0 Then
        strInstanceName = BuildInstanceName (strMacName, strInstanceName)
        Exit Function
    End If

    strKey = "SOFTWARE\Microsoft\" + strInstanceName + "\Cluster"
    GetRegValue "", HKEY_LOCAL_MACHINE, strKey, "ClusterName", strMacName, REG_SZ, b32bit

    If StrComp(strMacName, "") <> 0 Then
        strInstanceName = BuildInstanceName (strMacName, strInstanceName)
        Exit Function
    End If

    ' Provare ad eseguire una ricerca del valore del Registro di sistema per le istanze 2005/2008
    'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL
    ' RegValue = InstanceName
    strInstID = ""
    strKey = "SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL"
    GetRegValue "", HKEY_LOCAL_MACHINE, strKey, strInstanceName, strInstID, REG_SZ, b32bit

    If StrComp(strInstID, "") = 0 Then
        ' Se la chiave non esiste, tornare all'istanza locale SQL 2000
        strInstanceName = BuildInstanceName (".", strInstanceName)
        Exit Function
    End If

    strKey = "SOFTWARE\Microsoft\Microsoft SQL Server\" + strInstID + "\Cluster"
    GetRegValue "", HKEY_LOCAL_MACHINE, strKey, "ClusterName", strMacName, REG_SZ, b32bit

    If StrComp(strMacName, "") = 0 Then
        strMacName = "."
    End If

    strInstanceName = BuildInstanceName (strMacName, strInstanceName)
End Function

Function BuildInstanceName (ByVal strMachineName, ByVal strInstanceName)
    Dim strPrefix

    strPrefix = ""
    If StrComp(strMachineName, ".") = 0 Then
        strPrefix = "lpc:"
    End If

    If strComp(UCase(strInstanceName), "MSSQLSERVER", 1) = 0 Then
        BuildInstanceName = strPrefix + strMachineName
    Else
        BuildInstanceName = strPrefix + strMachineName + "\" + strInstanceName
    End if
End Function