解决ASP上传漏洞

<%@LANGUAGE="VBSCRIPT" CODEPAGE="936"%>







<%
on error resume next
dim upload,f_folder,file,formPath,iCount,filename,fileExt,filesizemin,filesizemax
'******************************************************************
'CheckFileType 函数用来检查文件是否为图片文件
'参数filename是本地文件的路径
'如果是文件jpeg,gif,bmp,png图片中的一种，函数返回true，否则返回false
'******************************************************************
const adTypeBinary=1

dim jpg(1):jpg(0)=CByte(&HFF):jpg(1)=CByte(&HD8)
dim bmp(1):bmp(0)=CByte(&H42):bmp(1)=CByte(&H4D)
dim png(3):png(0)=CByte(&H89):png(1)=CByte(&H50):png(2)=CByte(&H4E):png(3)=CByte(&H47)
dim gif(5):gif(0)=CByte(&H47):gif(1)=CByte(&H49):gif(2)=CByte(&H46):gif(3)=CByte(&H39):gif(4)=CByte(&H38):gif(5)=CByte(&H61)

function CheckFileType(filename)
CheckFileType=false
filename=LCase(filename)
dim fstream,fileExt,stamp,i
fileExt=mid(filename,InStrRev(filename,".")+1)
set fstream=Server.createobject("ADODB.Stream")
fstream.Open
fstream.Type=adTypeBinary
fstream.LoadFromFile filename
fstream.position=0
select case fileExt
case "jpg","jpeg"
stamp=fstream.read(2)
for i=0 to 1
if ascB(MidB(stamp,i+1,1))=jpg(i) then CheckFileType=true else CheckFileType=false
next
case "gif"
stamp=fstream.read(6)
for i=0 to 5
if ascB(MidB(stamp,i+1,1))=gif(i) then CheckFileType=true else CheckFileType=false
next
case "png"
stamp=fstream.read(4)
for i=0 to 3
if ascB(MidB(stamp,i+1,1))=png(i) then CheckFileType=true else CheckFileType=false
next
case "bmp"
stamp=fstream.read(2)
for i=0 to 1
if ascB(MidB(stamp,i+1,1))=bmp(i) then CheckFileType=true else CheckFileType=false
next
end select
fstream.Close
set fseteam=nothing
if err.number<>0 then CheckFileType=false
end function

function TrueStr(fileTrue)
 str_len=len(fileTrue)
 pos=Instr(fileTrue,chr(0))
 if pos=0 or pos=str_len then
 TrueStr=true
 else
 TrueStr=false
 end if
end function

filesizemin=100
filesizemax=200*1024
set upload=new upload_5xSoft '建立上传对象
f_folder=upload.form("upfilefolder")

'********************************列出所有上传文件***************************************************
For each formName in upload.objFile
set file=upload.file(formName)
If file.filesize>0 then

    '********************************检测文件大小***************************************************
    If file.filesize        response.write "你上传的文件太小了　[ 重新上传 ]"
    ElseIf file.filesize>filesizemax then
        response.write "文件大小超过了 "&filesizemax&"字节 限制　[ 重新上传 ]"
    End If

    '********************************检测文件类型****************************************************
    fileExt=ucase(right(file.filename,4))
    uploadsuc=false
    Forum_upload="RAR|ZIP|SWF|JPG|PNG|GIF|DOC|TXT|CHM|PDF|ACE|MP3|WMA|WMV|MIDI|AVI|RM|RA|RMVB|MOV|XLS"
    Forumupload=split(Forum_upload,"|")
    for i=0 to ubound(Forumupload)
        if fileEXT="."&trim(Forumupload(i)) then
            uploadsuc=true
            exit for
        else
            uploadsuc=false
        end if
    next
    if uploadsuc=false then
        response.write "文件格式不正确　[ 重新上传 ]"
        response.end
    end if

    '********************************建立文件上传的目录文件夹****************************************
    Set upf=Server.CreateObject("Scripting.FileSystemObject")
    If Err<>0 Then
        Err.Clear
        response.write("您的服务器不支持FSO")
        response.end
    End If
    f_type= replace(fileExt,".","")
    f_name= year(now)&"-"&month(now)
    If upf.FolderExists(Server.MapPath(f_folder&"/"&f_type&"/"&f_name))=False Then
        If upf.FolderExists(Server.MapPath(f_folder&"/"&f_type))=False Then
            If upf.FolderExists(Server.MapPath(f_folder))=False Then
                upf.CreateFolder Server.MapPath(f_folder)
                upf.CreateFolder Server.MapPath(f_folder&"/"&f_type)
                upf.CreateFolder Server.MapPath(f_folder&"/"&f_type&"/"&f_name)
            Else
                upf.CreateFolder Server.MapPath(f_folder&"/"&f_type)
                upf.CreateFolder Server.MapPath(f_folder&"/"&f_type&"/"&f_name)
            End If
        Else
            upf.CreateFolder Server.MapPath(f_folder&"/"&f_type&"/"&f_name)
        End If
    End If
    f_ftn=f_folder&"/"&f_type&"/"&f_name
    Set upf=Nothing

    '********************************保存上传文件至文件夹*****************************************
    randomize
    ranNum=int(90000*rnd)+10000
    filename=f_ftn&"/"&day(now)&"-"&ranNum&"-"&file.filename
    if TrueStr(filename)=false then
        response.write "非法文件"
        response.end
    end if
    if file.filesize>filesizemin and file.filesize    file.SaveAs Server.mappath(filename)   '保存文件
        if f_type="JPG" or f_type="GIF" or f_type="PNG" then
            If not CheckFileType(Server.mappath(filename)) then
            response.write "错误的图像格式 　[ 重新上传 ]"
            Set fso = CreateObject("Scripting.FileSystemObject")
            Set ficn = fso.GetFile(Server.mappath(filename))
            ficn.delete
            set ficn=nothing
            set fso=nothing
            response.end
            end if
            response.write ""
        ElseIf f_type="ZIP" or f_type="RAR" or f_type="DOC" or f_type="TXT" then
            response.write ""
        'ElseIf
        else
            response.write ""
        end if
        iCount=iCount+1
    end if
set file=nothing
end if
next
set upload=nothing  '删除此对象

response.write (iCount&" 个文件上传成功! 继续上传")
%>