Kesion cms sql注入漏洞修复及其分析

Dim KS:Set KS=New PublicCls
Dim Action
Action=KS.S("Action")
Select Case Action
Case "Ctoe" CtoE
Case "GetTags" GetTags
Case "GetRelativeItem" GetRelativeItem //问题函数
...skip...
Case "getonlinelist" getonlinelist
End Select
Sub GetRelativeItem() //漏洞函数开始
Dim Key:Key=UnEscape(KS.S("Key"))//漏洞位置，只调用ks.s函数，无其它过滤。
Dim Rtitle:rtitle=lcase(KS.G("rtitle"))
Dim RKey:Rkey=lcase(KS.G("Rkey"))
Dim ChannelID:ChannelID=KS.ChkClng(KS.S("Channelid"))
Dim ID:ID=KS.ChkClng(KS.G("ID"))
Dim Param,RS,SQL,k,SqlStr
If Key<>"" Then
If (Rtitle="true" Or RKey="true") Then
If Rtitle="true" Then
param=Param & " title like '%" & key & "%'"//类似搜索型注入漏洞。
end if
If Rkey="true" Then
If Param="" Then
Param=Param & " keywords like '%" & key & "%'"
Else
Param=Param & " or keywords like '%" & key & "%'"
End If
End If
Else
Param=Param & " keywords like '%" & key & "%'"
End If
End If
If Param<>"" Then
Param=" where InfoID<>" & id & " and (" & param & ")"
else
Param=" where InfoID<>" & id
end if
If ChannelID<>0 Then Param=Param & " and ChannelID=" & ChannelID
Param=Param & " and verific=1"
SqlStr="Select top 30 ChannelID,InfoID,Title From KS_ItemInfo " & Param & " order by id desc" //查询
Set RS=Server.CreateObject("ADODB.RECORDSET")
RS.Open SqlStr,conn,1,1
If Not RS.Eof Then
SQL=RS.GetRows(-1)
End If
RS.Close

Public Function S(Str)
S = DelSql(Replace(Replace(Request(Str), "'", ""), """", ""))
Function DelSql(Str)
Dim SplitSqlStr,SplitSqlArr,I
SplitSqlStr="dbcc|alter|drop|*|and |exec|or |insert|select|delete|update|count |master|truncate|declare|char|mid|chr|set |where|xp_cmdshell"
SplitSqlArr = Split(SplitSqlStr,"|")
For I=LBound(SplitSqlArr) To Ubound(SplitSqlArr)
If Instr(LCase(Str),SplitSqlArr(I))>0 Then
Die ""
End if
Next
DelSql = Str
End Function