Dedecms background SQL injection vulnerability(CVE-2023-27733)
Recurrence Process
Visit /dede to login to the website background.
An web-shell can be written in this page.
Code Audit
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
else if($dopost=="query")
{
csrf_check();
$sqlquery = trim(stripslashes($sqlquery));
if(preg_match("#drop(.*)table#i", $sqlquery) || preg_match("#drop(.*)database#", $sqlquery))
{
echo "<span style='font-size:10pt'>删除'数据表'或'数据库'的语句不允许在这里执行。</span>";
exit();
}
if(preg_match("#^select #i", $sqlquery))
{
$dsql->SetQuery($sqlquery);
$dsql->Execute();
if($dsql->GetTotalRow()<=0)
{
echo "运行SQL：{$sqlquery}，无返回记录！";
}
else
{
echo "运行SQL：{$sqlquery}，共有".$dsql->GetTotalRow()."条记录，最大返回100条！";
}
$j = 0;
while($row = $dsql->GetArray())
{
$j++;
if($j > 100)
{
break;
}
echo "<hr size=1 width='100%'/>";
echo "记录：$j";
echo "<hr size=1 width='100%'/>";
foreach($row as $k=>$v)
{
echo "<font color='red'>{$k}：</font>{$v}<br/>\r\n";
}
}
exit();
}
if($querytype==2)
{
$sqlquery = str_replace("\r","",$sqlquery);
$sqls = preg_split("#;[ \t]{0,}\n#",$sqlquery);
$nerrCode = ""; $i=0;
foreach($sqls as $q)
{
$q = trim($q);
if($q=="")
{
continue;
}
$dsql->ExecuteNoneQuery($q);
$errCode = trim($dsql->GetError());
if($errCode=="")
{
$i++;
}
else
{
$nerrCode .= "执行： <font color='blue'>$q</font> 出错，错误提示：<font color='red'>".$errCode."</font><br>";
}
}
echo "成功执行{$i}个SQL语句！<br><br>";
echo $nerrCode;
}
else
{
$dsql->ExecuteNoneQuery($sqlquery);
$nerrCode = trim($dsql->GetError());
echo "成功执行1个SQL语句！<br><br>";
echo $nerrCode;
}
exit();
}
|
The sql statement only prohibits database deletion, and does not prohibit shell writing through the SQL statement.
